Does a 1960 car have:

1. A front /rear bias valve, they can stick so clsing off th rear...
2. Split circuits? Again added complications!

53 year old hydraulic pipes will always be suspect and any flexible parts highy suspect.

I think a full replacement of all lines and parts would be prudent, especialy the rear cylinders. All cars with fromt disc and rear drum brakes are prone to suffer stuck cylinders ans they get so little use.

Peter,
66, 2016 Porsche Boxster S
No longer driving Tarka, the 2014 Plus 8...