I recently shot an sl8 and fell in love with HK quality. Shortly after I purchased a c93 (not here yet still getting compliance work done). I am thinking about getting a gsg5 sd and would like to put a collapsable stock on it. I am in new york and would need to make it fixed. Does anyone have any tips tricks or ways I may be able to do it. Thanks. I am aware neither guns are true hk's but I am working my way up.