I'm getting rather tired of seeing band amp failures due to the use of these flimsey domestic grade of amp headphone sockets. Even if you can get hold of one off replacements, rather than minimum of 100 , what is the point of like for like replacement if only 3 years of use, not abuse, leads to amp failure.
Current one carried a negative rail for switching purposes so definitely isolated switch action required. Starting with a standard 2 way or 3 way chassis or pcb mount socket. For 1 2 or 3 isolated sockets and continued use of the 3 tip/ring/ground contacts to an inserted jack. Rough up mechanically the outer surface of the moving contact. Solder, deliberately messily for later glue bonding, some highly flexible hookup wire to the end of a moving contact at the switch contact end. Open the contact and feed some 0.1mm or so plastic tape under and around the moving contact and wire, bounded by the channel in the socket plastic body. Blank off ends with blue tac or whatever and fill the channel with epoxy, except a few mm at the hinge end. When cured bend back the locking tang at the socket plastic and remove the moving contact and Dremmel/0.6mm grinding disc, slice a slot,on the inner side of the moving contact metal, between frog (as in brick frog shape) and the contact . Assuming it takes this mechanical action, without breaking away, add a little more epoxy slightly over the cut and also on and over the free end to beef up even more. Repeat , if required on other 1 or 2 poles for more switches. Mount perhaps upside down and wire into the pcb.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on