The Seeburg SC that I am currently working on had suffered from years of use an a fair amount of abuse.
When I stripped the wallbox it was obvious that both of the internal speaker cones were damaged, several tears in the paper of one and a small 1/4 inch hole & more splits in the cone of the other speaker.
As I wanted to try and repair these speakers I applied a small amount of PVA glue to the torn edges but also wanted to reinforce the tear with a patch on the rear of the cone first I tried with some kitchen paper but the paper delaminates when damp so ended up using small pieces of tumble dryer sheet & PVA glue, it works a treat!
Have just fitted them and given them a try, they sound as good as non repaired ones to me.
Cheers Scudie