Hi Dean, I think it's a MK1 but the telltale signs are easy to spot.
The MK1 has :-
Two scope arrester pin holes.
No antibeartrap.
The front trigger guard screw is 7mm diameter.
The underlever is retained by a simple sprung ball bearing.
The fore site blade is cast into the underlever retaining block and can't be removed without a hacksaw.
All the best Mick