Bullied Southern Railway "Merchant Navy" class Pacific, modified with air-stream casing removed and Walschaerts valve gear:

https://en.wikipedia.org/wiki/SR_Merchant_Navy_class

Spot on I think, thanks.

There is one of the similar "West Country" class pacifics "Boscastle" based on the GCR, so one day a similar view may be able to be recreated!
#34039 is shown here at "Leicester North" in January 1998.

The loco was rescued from Barry scrapyard in South Wales in the early 1970's and was restored to re-enter service on the GCR in 1993. Due to various problems, it was withdrawn in 2000 and with delays due to lack of finance within the owning group, it is only now on the way to completion again. I believe 2021/22 is the target date for this.

That would actually be a rebuilt “Battle of Britain” class. The Merchant Navy class was numbered in the 35000 series. The Battle of Britain class was in the 34000 series. Unlike the Merchant Navy class, some were rebuilt, and some weren’t.

I think the un rebuilt Battle of Britain class is one of the most handsome locomotive classes out there, as shown here by “Blackmoor Vale”, numbered with her original number, in original livery, and with what appears to be Southern Railway (Uk) painted coaching stock behind her.

Also, the merchant navy in the GCR video likely survives today. I can’t tell if the number is 35010 Blue Star, or 35018 British India Line. Either way, both survive.

The West Country and the Battle of Britain locos were all Bullied designed "Light Pacifics" and were numbered together in the 34xxx series....
Full list is here, but the WC's were generally named after towns/places served by the SR in the South West of England (like Blackmoor Vale. Boscastle etc) and the B of B ones were squadrons/airfields/personalities associated with the Battle of Britain in 1940. There are a few in there which are neither of these categories as well, just to confuse matters...
https://en.wikipedia.org/wiki/List_of_S ... ocomotives

Wait, when the hell did I type "Merchant Navy"? I MEANT to write BB Class.

Dang staying up too late.

Somebody more determined than me can go through the potential options (35010? 35013? 35018? 35019? 35030?) and compare the plate/crest to figure out exactly which one is portrayed......

Looks like 35018 to be honest.

Bit unusual for that to get as far north as Loughboro' in BR days, but the train does seem to have some green Southern Region stock in it so could well have been one of the inter regional trains that power worked through as far as Nottingham.
Couldn't find any record on the "Six Bells Junction" website of it working a railtour on the GC prior to closure.

No, I think you were correct. I was referring to the picture of 34039. The locomotive in the GCR video is 100% a Rebuilt Merchant Navy class because it has a 35xxx number.

The “West Country” class and the “Battle of Britain” class are essentially identical from what I know. Both are the light Bullied Pacifics. Excuse me for that because I have no idea what differences either of these classes have.

35018, British India Line in 1980 and 2018, lucky to be with us still after spending 14 years in the Woodham Brothers scrapyard in Barry, South Wales (Clive Warneford and Andrew ARG photos respectively), definitely looks like the same class (SR Merchant Navy) but I can't make out the number in the video:

It looks definitely like 3501X

It could just be, appropriately for present company, 35012.

"United States Lines"

An updated progress/appeal video has been posted to YouTube today...
https://www.youtube.com/watch?v=fAzSleAgQ9g&t=1s
They have currently raised just under £1 Million for the next phase of the work.

It will be an interesting test of post-covid fundraising for heritage railways, what they are asking for at a minimum is around $2.1M. I suspect they will raise that quickly, I think people are ready to go.

They actually launched the appeal for the current phase on 1st March last year, and the first UK Covid Lockdown came into play some 3 weeks later, so nearly all the money that has been raised so far (I believe its around £910,000/US$1.24 million) has been raised during the effects of Covid, despite all the competing "survival" claims from other preservation schemes that have been running in that time. Hopefully the momentum will be kept up in the coming months so that work can start as planned for 2023, if not earlier.
One problem with the scheme that was not mentioned, is that there have been various "problems" with the operations over the northern section of the line (Loughborough-Ruddington) following a visit by the Office of Rail Regulation. The bridge over the A60, which is mentioned in the video, currently is unable to carry any rail traffic until repair work to the structure is undertaken. This has halted the regular freight traffic from the National Network that used the line to access a Gypsum plant at East Leake and which provided commercial revenue traffic to that operation. Not a lot has been said publically about the whole episode, but talks are apparently ongoing to remedy the situation between interested parties, which means the timescale for the required work on that bridge as part of the reunification scheme may be brought forward.
The GCR (North) operation (a completely different entity to the "South" GCR Loughborough - Leicester North line) was forced to shut down all operations - including access to workshop facilities used by various groups based there - after the ORR inspection, and no date has been announced for the resumption of train services as yet. It was supposed to be this holiday weekend, but that didn't happen.

Another significant (over £1 Million) phase of the scheme has now been given the go-ahead....
https://www.gcrailway.co.uk/2022/04/gre ... placement/

For fans of "Top Gear," I'm pretty sure this is the line on which they filmed their hilarious "caravan train" segment (which if you haven't seen, you can find on YouTube, it's one of the funniest things I've ever seen on TV with trains).
As for the news, like the rest of you, I'm very pleased to hear that.
I strongly feel the English have a far greater interest in rail preservation as there seems to be a general across-the-board higher interest in preservation and completed projects than you see in the US.