I'll remove a stock off one and post a few pictures up tomorrow.....I had a tx200 MK1 that shot sweetly due to having a shorter stroke compared to the MK3
I have 3 bsa super tens 2 hw100s 3 hw80s a Diana 52 running a 25mm piston (shoots like a fly has landed on your hand) a fwb 124 sport in my own made stock and my first airgun a 1985 bsa airsporter carbine in .177 that I bought new plus lastly my mk1 hw 97 in .22