K-37 Tenders.

All of the photos ive seen of K-37's, i've always liked to look and see all of the differences on each one. Like 492 had a Nathan Lubricator, stuff like that. One thing that i've always been curious about on K-37's is the tenders. They are almost all different in the height of the coal boards. Did the D&RGW really have drawings for the tanks on the K-37's? Im sure they had SOMETHING to go off of. I suppose some of these changes could have happend because of wrecks or something.
Another question is, 497 in the late 60's had a different tank than earlier days. Did it get 490's tank? It looks like it did because the 490 had really tall coal boards. They really aren't coal boards, I can't think of what else to call them though. Where the tank raises up above the coal space...
Thanks alot,
Kevin M. Bush