Help with a newly acquired old Heuer

I recently acquired this 3647 Heuer Carrere. It is fitted with a Valjoux 92 movement and I believe it is a model 45, SN 66311. The case is marked 106335. I believe it was made 1964/65. The condition of fine, but I need to repair or replace the return pusher; I broke the shaft removing the back--don't ask. Anyway I've searched the net and talked to some suppliers but cannot find a new or used replacement pusher. Any ideas? I would also appreciate any information you can provide me about the watch. Thanks, JLH

Maybe best course of action would be to take it to a watchmaker and find out what it needs.