So on Paperlab's advice I got some of this stuff of Amazon:
First impressions weren’t too good - very gloopy, and fast drying similar to EvoStick contact adhesives. However, I used it on some test pieces, and it goes on ok with a cocktail stick. I’d describe it as resulting in a bond - at least initially - similar to a post-it note. It remains fully peelable for at least half an hour - which is perfect for positioning large parts. I think it may stay peelable, because excess can be rubbed off quite easily.
My plan is to position all the main hull sub-assemblies with Elmer’s, then wick PVA along all the external joints to make a final, stronger bond.
Thanks Paperlab!