Two ickle things getting between me and my new clunker.

First the star fangled nut in the 2nd hand forks has a hex socket…? it reminds me of carbon fork bungs but won't respond to adjustment -corroded? i think its a 6 or 8mm one. why is it there? what does it do? and if i need to trim the steerer is its differentness gonna allow me to reuse it.

Secondly I stupidly only checked the park website when directing the bike shop to fit the truvative externall bb and they don't mention spacers when, of course, i actually needed three, according to the official instructions. so i fitted it and am now wondering if i broke it (imagining the little tube inside got very squashed against the inside faces of the bb) and where to get the spacers, for when i do it properly, anyone got spares? at the moment too shame faced to go back to the bike shop.

thanks, sorry to be confusing