Well, after receiving Neil's excellent guide to disassembly / assembly of the original 75 and having another go at mine this weekend all I can report is that I'm still stuck despite having spent over an hour making a spring compressor specifically for the job, and sucessfully getting the giss system back together, the original problem still seems to be present.

Basically, when the action is fully assembled but out of the stock, the gun will cock including setting the trigger. When the trigger is "pulled" there is a very loud click but the gun doesn't fire I can then decock the gun if I pull the cocking lever all the way back ( resetting the trigger to the fire position manually otherwise pulling the cocking lever back will break the tang off the rear hook - tell me how I know this ) then lift the safety lever up whilst slowly returning the cocking lever to the closed position.

I've studied the mechanism over and over again whilst pouring over just about every picture, stripdown and info I can find and I still can't find what's going wrong

The only thing I could do with, and it's a long shot, is to find the side images of the action when the gun is cocked, to see if when mine is cocked, all the parts are in the correct cocked position. This might give me a clue as to if the parts are moving correctly. So.....does anyone have or would be willing to take pictures of the cocked Original 75 action out of the stock, a big ask I know and it may not even help but I'm as you can see, getting a bit desperate

My last option would be to see if anyone on here with more knowledge than me on these guns, would be willing to have a go at it. ( I believe I've seen somewhere on here that Dave Mercer is the man to ask? )

Norm