Defensive much? Nobody even said anything critical of them.

Evidently some folks took my comment about swapping pistons and rods with #1308 as being a criticism of the WMSR mechanical department. In the words of Richard Nixon "Let me make one thing perfectly clear"... They know the whole story, and we don't. And, they know WTF they're doing (OK, let me make TWO things perfectly clear). If you can spare a little dough, please consider contributing to the cause.

Next time I'll keep my wisdom to myself.

How dare you try to discuss preservation on this board - I’m glad you’ve learned your lesson.

The pistons were in good shape during the rebuild. So, what happened on the WMSR to cause this issue?

No comment.

More than one Nixon made things perfectly clear.

Ouch.

"I am not a crook."

How would have figured this out in a hurry running something multiple times a day would wear them out. Yes I know that the pistons get lubricated via steam oil injected into them. However you can not take something that was stored for years without any maintenance on it especially outside storage put it back into service without expecting some items to wear faster than you thought. In car terms it would be like taking a barn find 57 Chevy changing the tires battery and fluids then expecting it to be a 40 mile daily commuter. It is NOT GOING TO HAPPEN.

To use your analogy, the WMSR reportedly did do a ring and cylinder/piston job on it. There was literally no way they couldn't have. Either they didn't do it right, they used inferior material, or somebody just done plumb screwed up somewhere.

I've had to have a professional, reputable garage, referred to me by a car collector associate, buy and replace an engine for one of my cars years ago because they did an oil change (along with the other work on a CV joint) and forgot to refill the oil. One test drive and leaving the garage later, it was toast, and we literally pushed it back to the garage from the traffic light down the street. The specialist dealer to whom I sent them in search of a replacement engine, when I came by to tell him the story and check his inventory, pointed down the road and said "You see that Jiffy Lube down there?.............. they buy an engine off of me about every two months, and all I have is certain GM engines! I don't even want to know what happens to everyone else!"
Needless to say, I started changing my own darned oil........

These engines ran millions of miles in daily service hauling as much freight as they were rated to pull. A couple of short trips a day hauling passengers it should be able to do almost indefinitely. The same as that '57 Chevy, with proper maintenance, they drove them every day for years when they were new. My daily driver is a 1994 and I'd go anywhere with it that didn't have too many hills, it's underpowered and doesn't do well on them.

1309 operated in Mine Run service, hauling loads and empties between marshalling yards and the mines. It was not used as a line haul engine running from a marshalling yard such as Clifton Forge to tidewater piers at Newport News or moving coal from Russell, Ky to the Great Lakes docks at Toledo. Its life was relatively short moves every day with a lot of switching taking place.

"Sh!t happens". Even new parts fail sometimes for random reasons. To further the automotive analogy, I changed out an oil pump with a brand new one and the maximum pressure it could do was 20 psi due to an undetected manufacturing defect. These are simple affairs so what could possibly go wrong?

When rebuilding old tech, sometimes it takes a while for a problem to crop up. If anything can go wrong, expect they will at inopportune moments until the all bugs are worked out. With each piece, you learn its individual quibbles as you go.