man dude ! owch thats a peice of precision engineering!,well if u ever wanna take bolt or grub outa tight thread always give it a little tighten first to crack the lok & then back off then turn back then back of etc like tapping & theres an old saying the 1st rule of engineerring is keep it simple !~ wish i were there to do it 4 ya m8,look after ya impy
& most of ya threads r imperial so theres a little differance as in 1 is tapered & the other is parralel ,so be careful coz were metric & imperial threads r pretty nuisance to get hold of in uk.if u r ever stuck always go to an engineers& tool makers stockist for ya bits & bobs