I ordered an 18" long 3" OD ABS tube from Plastruct.  It would not be long enough to do both the boiler and smoke box.  But, when I looked around the shop, I saw that I had a piece leftover from when I built the boiler for the ten wheeler.  The tubing is 5/64" thick and I calculated that if I cut out a strip about 7/16" wide, that would be just enough to make it so this could fit inside the long boiler tube. I cut it out, filed the edges straight, and then glued it back together using Weldon 16.  This now fits inside the long boiler, giving me the look I wanted.

I put the rivets on some styrene and then wrapped it across the smoke box; added builders plate, clean out and headlight bracket.  I cut styrene to shape and added some plastic nut/bolt/washer castings.  The stack was fashioned from some styrene tubing.

Gary Buchanan had offered to make some appropriate domes for me using the EBT drawings as a starting point.  They turned out perfect.

I added some details to the smokebox door; smokebox dogs, number plate and grab iron.   I used some narrow styrene strips to model the bands around the boiler.