I will asume your guitar is USA made cause a can see a cero stamped
, This kind of tuners are originaly schaller ( the masters tell me if im wrong please ) , so if u cant find a hamer logo replacement , a good option can be buy 6 schaller tuners may be? Cherrs
I think all the Calis had same constructions ways, the experts members here can tell us if im wrong , i add a pic of my Cali showing the back
I hope they are useful to you👍