Rebuilding Shimano 105 brakes

Hey everyone,

I recently bought a second-hand road bike (1993 Giant Cadex CFR1) which has Shimano 105 componentry. It all seems to work well, however the bolts for the brakes are a bit rusty and I would like to replace them.

I've looked online for a rebuild kit, but either my searching skills are poor or there isn't really anything.

Is there going to be an easy way to go about this? Can I buy these brake bolts online, or should I ask my LBS if they have some better condition extras lying around?

Finally, is there a difference between older and younger 105 bolts, and also other Shimano brake bolts?

Thanks for reading!