Many thanks RustBuzz for your response.
The barrel is 14 and 3/4 inches long. It does not have a breech pivot pin, a bolt/screw. The trigger is metal, not plastic, it is smooth in operation, I have not made any adjustments to it, I would not say a two stage, just a little pressure and very small movement before the positive release. The whole rifle is smooth to shoot. The breech block is stamped MK2 as per the ASI sicker. The Mastersport sticker is oval in shape with a black background, the Mastersport text is silver, the outer edge border looks to be a metallic green. I have not taking it apart to look inside, being as it is very rarely used and seems good and well, I am reluctant to have a dabble inside at this moment in time.
All the best.....