I absolutely can see someone adding a power booster. It’s not uncommon at all. It’s amazing all the little things you’ll find that people have added to a 50 year old car, and if they added it 30 years ago it will look original.
Ahhh. Good to know! Maybe I should have left it off the build, to keep it original then. If that’s the case. Looks like if might be, since the code for brake booster isn’t on the fender tag