Jammed Cassese CS79 Underpinner

[Jarvman]

Hi all, in a slight crisis here. Got my Cassese CS79 underpinned jammed up with 2 V nails. Does anybody know if there is a way of dismantling the machine to release them? I've looked at the instruction manual and it suggests the place where the V nails are fired up can come apart. It says this can be done using an allen key, yet I can only see a screw thread where it shows. Any help would be appreciated a lot. I can take some pictures of the problem if this helps. Much appreciated. Cheers!

[easypopsgcf]

Fairly sure there are 4 small allan screws, which are at each corner of a split block which is the housing that the firing pin(hammer) slides up and down.
The screw you might be seeing could be the small one that holds the hammer in place.
Stick up a picture and that might help