My father repaired them (a Sgt Chippy) his RAF text books came in handy when I built an MW6t. I used the same glue (lactose based). The PFA inspector I used insisted on sample birch ply joints (both scarfed or otherwise) being kept in jam jars of water every time I mixed a new batch of glue. I had to date them and test them annually over a few years. Never a problem. The only real problem was a fungal growth which by the time I was building had been sorted with a coating of red fungal dope.To my knowledge they weren't glued together on someone's driveway in varying conditions and on unknown paint quality....
To be honest I think the only issues they had with ww2 mosquitos was in certain climates where the resident insects consumed the glue used.