dig out old pad on arm.replace with a bit of leather cut to shape.glue in with epoxy.the seal ,i used a webley synthetic seal.allen head bolt with norelock nut.the spring chuck it.on the cocking arm use a vice and carefuly close up gaps on linkages as they tend to part with tough springs.once you have it apart.leave loading tap in .look down cylinder through tap and down barrel..slightly open tap you should get an evern eye opening as you turn it.if not you can shim tap to improve it ,debure cocking slot and cylinder with wet n dry and oil .polish with autosol.these rifles are slated by many ,but can be as good as most of the time with a little attention.you dont want a powerful spring in it .6 to 8ft lbs is a good level ,without wrecking the trigger,make a spring sleve from biscuit tin this will help power and smooth action.most you may have ,its about the best tune you will do and cheap too.oh smooth cocking slot in piston too.solid bit of metal.enjoy.