The joint pin in this gun based on the photos, is a loose pin. Whether it is a screw or just a knock in is impossible to say. However the caps that cover the access will have been screwed in and filed off ,as there is no screw driver slot the only way to will get them out is to drill them . I've been at this for years and it is very very rare to get them out without damage.
The outcome of this is that new caps will have to be made ,engraved and will never colour to an exact match. Personally I always thought this was a daft way of doing things,but that that's how they were made.
Most Hinton guns I have seen have been quite well finished ,mid quality actions .
