Professional picture framers use a very fine double sided stick tape. Its known as ATG tape.It is paper thin and is acid free. Comes in roll about half inch wide. Works real well, very strong. It is wax paper backed, easily roll off. Easy to removed, can be layered up. Helps with twisted panels. Also works on cassette door panels,nearly see through. When glue just won't work or as with crazy glue can heat the metal up ,changing it tone. This stuff work great. "Adhesive transfer "G stands for gun" which it is applied with.Most framing shop should have it around. A  roll is about $ 7-8  My wife say it rarely found out side framing supply, not like the double sided tape in hobby shops, this stuff is pure adhesive. Hope this helps Cheers,Bryan

Another workaround might be to embed four magnets in the body and stick four flat thin steel washers on the inside of the panel so that the panel stays on magnetically?