After looking at the filling I did, and then painting, weathering and installing the chimney, I think it will work. I remade the flashing in several pieces although it you look closely, it's still not correct since the front piece has little wings that are lying upon the side piece providing a path for water to get under the flashing. I'm leaving it all alone. I haven't used any weathering powders yet which will dull it down even some more. Some of the resin defects actually lend some more character to the piece.
The J-B Weld fastened the track into the new position perfectly so the tracks at the hinge are aligned. There was a bump from a bit of excess epoxy that I cut down to smooth passage over that area. I also replaced two traction tires on one truck of my MTH Union Pacific U50-C. I had a heck of a time getting the truck to motor screw installed and had to take the shell off so I could hold the motor still while aligning the truck. The motor kept drooping forward which put the screw out of alignment. I even tried using a brass rod to hold the screw holds aligned, but when I took the brass out to replace the screw, it was out of alignment. This simple little job took over a half hour. I still need to buy a new shell for this engine. When the shell fractured, it also fractured the standoffs that the shell screws tie to a and those ingenious contact devices MTH uses. You can't tell from a distance that the shell was completely fractured, but you better not pick it up by the body. That engine is now being reissued as a PS-3 so maybe that shell can be purchased.
I then found some black coated adhesive paper that comes with Bar Mills kits and it would make terrific flashing since it's already got the sticky stuff. And it's thinner than the construction paper I was using so it will be easier to slide the main roof next to it. The reason for this discussion is that I can now fully shingle this roof before installation, thus giving me more to do while waiting for the gutter brass. I'll start shingling tomorrow.