I actually installed a 1/4 inch t-nut into a piece of wood I'd drilled a hole in, then trimmed the wood to the size of the bottom of the Polaroid camera, varnished it, and expoxied it on. That was 20 years ago, and it's still working fine. Oh, yes, the head of the t-nut with the teeth was on the inside surface of the wood so all that you saw on the bottom was the hole with the threads of the t-nut a bit inside -- the wood being thicker than the size of the t-nut.