Issue with Shutter

[House]

While I was out today with my Mamiya Universal I noticed that the trigger on the Type 3 back felt a little stiffer than usual, but I pressed it anyway. I noticed this pin, pictured below, fall out. It looks like it has fallen from this spot, which triggers the lever above. I can no longer trip the shutter with either the Type 3 back or trigger on the hand grip.

I'm not entirely sure if I've broken something, of it's come loose and can be easily repaired.

 

[AgX]

It looks like it has fallen from this spot, which triggers the lever above.

It definitely was riveted to that protruding triangle, in contact with the release lever, and you forced it off.

But without having the lens at hand I am not sure of its function.

 

[House]

It seems to act as an extension so I can use a cable release connected to either the grip or film back. The shutter still works, but i've lost the ability to trigger it with a cable, so it's now even slower to use. It doesn't look like I could fix it without a donor lens, but I hope somebody can prove me wrong.

 

[AgX]

The cable release actuator on the other side of the lens pushes by that pin the manual release lever? I see.
Then it was not you forcing it off by releasing but it seemingly sheared off by other circumstance.

You could cement it back into position. With good surface preparation that should work well with epoxy cement.

 

[House]

The cable release actuator on the other side of the lens pushes by that pin the manual release lever? I see.
Then it was not you forcing it off by releasing but it seemingly sheared off by other circumstance.

You could cement it back into position. With good surface preparation that should work well with epoxy cement.

I'm not entire sure how it sheared off to be very honest, but I'm glad I noticed it as I was standing on the edge of a dock when it happened. Thank you for your input AgX, it's very much appreciated.