Erik,
Nope, I it's John's.
MWB,
The ends are Grandt #11. Yes, Grandt says they're for NG cars, but as far as I can tell, they are 72" diameter and work for smaller cars, such as the 6 compartment cars we're talking about here. I've been told many of the Colorado NG cars used tanks with the same dimensions as standard gauge cars of the era. Is that true? ****ed if I know but it sounded good to me!
I machined the ends of the tubes, using a lathe, so the ends would be inset (just like the prototype) and also had to remove some material from Grandt's castings. I did this by gluing a small stud to the inside of said casting, chucking it in the lathe, turning it to the desired dimensions and removing the stud. I'll attach a few photos in a feeble attempt to clarify.
Jay
