IF in the course of restoring a piece of rolling stock (say a 19th century wooden freight car) it is discovered that holes were mistakenly drilled in the sills (such as for a needle beam in the wrong place), does best restoration practice require that such holes be drilled in the replacement sills?

Photo document original (including measurements), make note of it in the artifact file. Unless the error helps tell the story of the artifact, I would not feel it necessary to repeat it.

I would be inclined to replicate the factory errors as that is how the artifact existed. If a wooden car is being restored, the wood should be old wood-preferably of the same type and age used on the car. If that is not possible, it would be acceptable to use newer wood of the same type used on the artifact.

Questions like this are classic examples of why preservationists should avail themselves of resources like the Heritage Rail Alliance conferences. In a previous conference in Washington, D.C., we had a visit to the Baltimore and Ohio Museum and this very topic came up during the visit to the restoration shop where they were working on the Camel and the Thatcher Perkins, repairing the damage from the roof collapse. The restorer described the conservation methods and replication standards that they were working to. The replacement wood was of the same tree type and age matched when possible. Much of the wood was sourced from old barns and buildings. The metal fasteners were made of designs appropriate for the age of the locomotive concerned. It's one thing to attempt to describe something like this in writing. It's something else entirely to have a professional restorer demonstrate it in person.

I restored a 1920's Plymouth Model BL (with help from other museum members). These are small loco's, 4 wheels, 50 hp, friction drive transmission.

Along the large cross shaft for the transmission (4" OD x 4 ft long) are two quill keys. These run the length of the shaft and a large bushing slides back and forth along the shaft.

The keys were 1/2" x 3/4" cold rolled steel attached to the shaft with flat head screws.

One of the original flat head screws was missing. I assumed it fell out, nope, in that hole was a broken tap (from 1920). There were no signs that anyone tried to remove it, they just snapped it off and assembled the machine with one screw missing. Heck 3 out of 4 screws should work until the warranty is expired ?

Since it was a spinning shaft and a loose key would be dangerous I decided to grind the tap out (diamond point) and use a thread insert (Heli-Coil (tm)).

It may not be original fabric, but it is now safe to operate.

I could have saved the dust from grinding out the tap, but why ?

Cheers, Kevin

I had a rather heated discussion in my younger days with Bob Bruneau of IRM (now passed on) about repairing damage. The Illinois Terminal center door car 101 had a large crease in its side sheet, and I was going to work it out with Bondo since I was doing other body filler work, and he said I couldn't, since we were going to repaint the car in the green and cream scheme, and the crease was there during that period. I said, come on, how do you know when that dent happened? He said he didn't know, but it predated the application of green and cream, because it shows in photos when the car was still orange. We left the crease.

The crew restoring SP 9010 had such a quandary, when the unit was painted in Germany when new, the "kerning" of the road numbers on the side of the cab was incorrect, essentially the numbers were shoved together too tight. I believe they have decided to paint them back in the incorrect original manner, because it is just part of the story of the locomotive (Unknown photographer, from the SP 9010 FB page):

I like the idea of accurately reproducing details that represent the foibles of mankind. The only issue I have is how do we differentiate between intentional vigarities and errors that we make which were not in the original record? How does a future historian know that a discrepancy is an accurate reproduction of the past and not a new defect?

Before you say document it, which is important, we need to accept that there is no way we can guarantee that the record will remain with the artifact, nor can we guarantee that someone is going to take the time to read the written record to understand our intentions and efforts.

Short of labeling the defect with indelible ink on the artifact this issue presents a problem for which I see no easy solution.

That said, reproduce the defects and let the future sort itself out.

CCdW

All that and document why the defects were reproduced. That way, the next person to work on the piece understands the context of the artifact's condition.

A set of markings being in a slightly odd spot is way more obvious than an extra hole drilled incorrectly in the past.
In the case of the SP KM unit, I agree that the markings should match those in-use as close as possible. But if the folks at KM had put an extra hole somewhere? Nah.
This reminds me of the story of when the Russians got their hand on a B-29 for the first time (from a forced landing in the Soviet Union while re-arranging the Japanese empire, which Russia was neutral in at the time). Stalin's boys said to reverse-engineer it exactly and build many more. The Tuploev engineers noted some battlefield repairs and wanted to not include them. Nope, they were told., Comrade Stalin said exactly (other than the different writing and the differences between Russian metric and US Imperial measurements and different armament on the finished planes), or you spend life in Gulag!
It came as one heck of a shock to the West during Aviation Day parade on 3 August 1947 at the Tushino Airport to see four "B-29s" flying overhead when everyone knew the Russians only ever had three that could have flown. But one of them, according to aviation lore, had the battlefield repairs of another re-created in the skin.