Yes, I was thinking about B&SR 7 also. SR&RL 10 and B&SR 7 were very, very similar engines, though I think 10 was a little bit bigger and closer to B&SR 8 in overall size. I can understand the desire to model SR&RL 10 because of the historical mystique that surrounds her, but a close inspection of B&SR 7 at the Maine NG Museum might be in order as a way of verifying certain details of construction -- especially since 7 is currently under restoration, i.e. still largely in pieces.
Here is 7's builder's photo in comparison with 10's:
-Philip Marshall