When I lost Amaya, I needed a reminder of her everywhere. I had an angel hanging from my rear view mirror in my car, I had a poem in a frame at my desk at work, I made a special bear with wings at Build-A-Bear (crying the whole time - the cashier gave me a hug) My husband stopped me at the Shadow Box. I made it anyway and put it in the spare bedroom. I told him that when he is ready that I will put it in our room. About a couple of weeks later, he was ready but he wanted the box on my side of the room (Sometimes I catch him on my side of the bed looking at it.)
As for the adhesive, try asking the people in the craft store. Tell them the objects for the shadow box. There is a glue called "Gorilla Glue" (I think). It is supposed to work on everything. Let me know if this helps.
Amaya - HELLP and severe Pre-E at 21 weeks