Nice job on the replica tube for the cap!
Is that a water slide decal?
I've used the vinyl hot-glue without any problems. But I think the dams you made are a good idea. I worry about the heat of the glue damaging the capacitors. I think polyester film caps are o.k., but polystyrene or polypropylene might melt. I think the hot-glue melts at a higher temperature than the wax.
John