Ours is going to be #1604 that is housed at the B&O Railroad museum in Baltimore. My son is obsessed. Tony's work introduced us to Big Ben's Bricks and helped when I found myself stuck a few times.
I have not finished the tender or done any of the underside detail/hoses yet, but I used 2x2 mod plate ball and socket "trailer hitch" to articulate the rear bogey of the tender so it looks the part of a 6-8... not sure how I am going to power the thing, one PF truck in the front of the tender may not be enough.