Hi Bret,
I remember looking at the boilers at McEwen and trying to place them to the locomotives they belonged to. By counting smokebox door dogs and bolt quantities, noting where builders plates were, cleanout plugs, pilot brace bolt holes, dome cap styles, and other items I've since forgotten (10-15 years ago now!), I think I came to the conclusion we had the boilers from the following:
1. OLC #102
2. OLC #104
3. The Eccles Climax (#1?)
4. The OTHER Eccles Heisler (#2?)
Along with these, lets not forget that the BWP #3's boiler went to Roaring Camp. Not a bad collection that remains!
All those things being said, I think the photo of the boiler is indeed the #100's...I just can't say with certainty it's one that is sitting in McEwen. It would be really neat if it is. Maybe we should all get together soon and do some in depth examinations and compare notes and ideas in order to determine what the railroad really has.
Casey