Since I couldn't put the seat tube through the top tube in a sound fashion. I added and short mono stay tube to the back to give it the illusion the seat tube is going through the top tube.
This crap . . . errrr I mean cap was more of a challenge than I thought. It started off as the square piece of 2"x2", .025, 4130 sheet. Then I snipped it down close . . . Then I had to bring in the heavey equipment. As I've said before. That's a rotary file, and it's not exactly anybody's friend. While very effective at shaving something down, it also leaves steel splinters in it's wake. A large magnet works great to pickup most of them, but I'm sure tomorrow I'll find a few more.