As a kid, I used to take small radio speakers from my home projects to a local speaker rebuilder. How I remember all the cones of different sizes stacked on wooden pegs on a shelf, and the sleeves of voicecoils and stacks of spiders. One thing I specifically remember is that they used a clear cement for assembly that they dispensed from pump type oil cans, the type with the long spout and the trigger on the side. I believe this was GC Service Cement, which is specifically designed for speaker repair. I have a small bottle of this cement with a little brush in the lid I got from a local wholesale electronics supplier. My memories are from the 1960's. OH, and they also used small scraps of motion picture film as shims for the voicecoils.