1967 Vox is oldtimer. It's very easy for some caps to dry up.
In order not to get unnecessary damage during the first inclusion build your own current limiter for protection when repairing and testing.
Current limiter for protection when repairing and testing electronic equipment
When servicing an amplifier, try to stay as far as possible the original state.
This means that only defective parts need to be changed.
Vox schematics is here: