Totally Unprofessional Opinion

I remember looking at the 20 many years ago when the jacket was off. I remember the running gear was toally worn out - but repairable.
The boiler was another story. I remember a bunch of "chewing gum" welds in the firebox. The real scary part was the steam dome rivet heads that had literally exploded from the combined forces of years of wet cinders trapped in there and the trapped water freezing, plus there was a big dent in the shell on the left side below the steam dome. I always have assumed the dent was from the wreck it had with the 40 on Cima Hill in 1943. The 20 and 40 both laid over on their left sides. I think the 20's fireman got killed.
The old story goes that the RGS guys told Uncle Bob R. to "never fire that thing up" as it had some terminal defect that they managed to hide from the ICC inspectors for years.
In as much as I believe that if an old boiler can be fixed, it should be fixed instead of replaced, I'm afraid in order to see the 20 in steam again, it will probably need a new boiler.