OK, making progress on the two winter projects; for the replacement decals that I do need, Greg at Cyclomondo had almost everything except the Atala's main down-and-seat-tube panels. OK, there's a few chips in the dark navy blue that I can try to touch up, but the edges where the two ends of the "wrap" meet on the backside show a little edge curling. The "curl" part is stiff. Any ideas on how to get it to lay flat for re-gluing, and recommended glue to use? Pan B is to trim the curl, and just use a lot of navy blue touch up paint, but I'd like to avoid that.

Maybe use rubber cement under the edges, tape flat and rub excess off after it has cured.........or contact cement applied very lightly.
Best, Ben

Use a hair dryer with care and warm the decal. Once warmed, it should be more pliable. Then glue it down and hope for the best. Been there and done this more than once. Even a good idea to seal the edge with clear after.

Contact adhesive will work well. Brush a little on the frame and a little on the back of the decal. Let dry thoroughly and and press together carefully from the center to the edge.

Yes, the only thing I would have added was to use masking tape (straight line) along the edge of the decal that is still holding strong to keep a clean edge ( leave room if there is overlap from loose decal) when glueing.
Rubber cement will just rub off cleanly with very little effort...........contact no so much, so it's better to keep every thing as clean as possible.
Been there, done both, light contact is the best when used sparingly/lightly........
Best, Ben

Good stuff here. Of course, I have neither rubber cement nor contact cement here at the moment. I do have some tiny glue applicators which should help.

Thanks!

Wow - it worked, apparently. I used a hobbyist's glue applicator (looks like a Q-tip with a pointed tip, and firmer), waited an house, pressed into place and lightly burnished with a firm scrap of plastic. Hopefully, it will hold.

If you're worried about it not holding up until completely dry you can hold it down with electrical tape wrapped in the opposite direction, then peel that off after a day or so.