I've find old rubber does harden up with time and they'll likely be next to useless (when they were new, ha!).
Shimano shoes are same shape from about 1990 onwards, so you can just stick the coolstop inserts in them. Salmon are rumoured to be the best, about to order some myself to replace some jokes ones I got from CRC, which were super soft and decent when new, but 1yr down they line they are like blocks of hardened plaster, useless, just make a mess of the rims.
I've find old rubber does harden up with time and they'll likely be next to useless (when they were new, ha!).
Shimano shoes are same shape from about 1990 onwards, so you can just stick the coolstop inserts in them. Salmon are rumoured to be the best, about to order some myself to replace some jokes ones I got from CRC, which were super soft and decent when new, but 1yr down they line they are like blocks of hardened plaster, useless, just make a mess of the rims.