Well, sectioning the larger T12 FTC tube worked out perfectly. The sectioned tube curled and a 29mm motor fits nicely. This tube also fits well in the T8 body. The F15 motor is a little snug but still inserts just fine. The section tube extends out the back about 3/8" and I built up a thrust ring with clear packing tape. I also taped the two tubes together.
Back to the nose cone!