Show us a picture?
I'd either find a way to position the parts so that they go right where they belong, or if possible, find a way to glue them up so they don't have to be super precise.
If you can live with Titebond's 10 minute working time you could just use that, although "pressed thin between glass" means that, first, you'll need to give it a lot of dry time, and second, it'll never fully dry while it's pressed between sheets of glass. I have, contrary to many dire warnings, laminated large sheets of balsa and/or plywood onto fuselages using SigBond, and have not had problems with them drying out --
but I build with awesome and ponderous slowness, so if I get my fuselage all laminated up today, then chances are it'll have weeks or months to dry before it sees paint.
Epoxy pot life assumes some self-heating in the pot (epoxy cure is exothermic). If you're paranoid about it kicking off too soon, mix it up then put it on ice. Or remember that when you spread it out thin it
won't heat up, so you'll have a longer working time. For spreading thin layers of glue, I make up spreaders out of plastic fake credit cards with notches cut in the edge. To make a thin (on average) layer of epoxy you just sweep that over the balsa; what's left is little ridges of epoxy to match the notches in the card. You'll spend time making the sweeper, but not using it. Or, if a really thin layer is enough, just sweeping balsa with card will leave epoxy in the grain of the wood -- doing both sides of a piece should be enough for a laminated bond.
This thread and
this thread have profile fuselages that I built up with inner balsa framing, sheet on the outside, and plywood doublers (even triplers in one case) on the nose.