1 Shaller tuner
 

My tuners are 34 years old. I replaced the Chrome buttons with wood. The A string tuner slips, and on two occasions has come apart.

Repairable or replaceable, and where can I get just one replacement?

You will have trouble finding one tuner. Especially one matching tuner for a 34 year old set. Large distributors won't bother, and smaller distributors will not carry the stock and may not order often enough to meet your needs.

Buy a good full new set.

Matt, pm or email me. Might have some one off parts for this.