PH rifle ID

[PeterN]

I have a PH 1200TX and was thinking of putting a scope sight on it. However, this rifle appeared at a local shop with a scope already fitted that looked cheap to me, so I went to look at it and bought it.
I am not sure exactly what it is. The serial number is R-23600. I have been comparing it to my 1200TX and there are differences. The barrel on my 1200TX is 23 1/2 inches long and this is 26 inches long. The barrel markings on the 1200TX read from muzzle to breech and on this rifle read from breech to muzzle, if that means anything. It just has 7.62 NATO and Parker-Hale Ltd, Birmingham, England. The barrel has a 12 inch twist. The scope sight blocks are steel. It has a four round magazine. The trigger guard and magazine base plate are alloy. The TX safety is flat with a couple of lumps on it but this is a serrated thumb type safety. It seems to be stuck in the fire position as I can't pull it back to the safe position. The butt is configured for the spacers but is fitted with a 1 1/2 inch solid wood extension. There is no butt sling swivel, only the one on the hand stop. The rifle came with the foresight and the PH5E back sight that has the fitting to clamp on to the rear scope block. The rifle has the conical bolt handle and my TX has the full ball handle. The serial number is electro pencilled on the bolt.
The scope on it is a fixed 20x42 mil-dot badged as Edgar Bros. It seems to be the same scope as the SWFA SS and I think it has been badged as Tasco also.
I would be interested if anyone can tell me more about this rifle, even if it is only an early 1200TX that has been re-barrelled with a butt extension.
Regards
Peter.