gasket ,seal if the gear is still good why buy another one unless your over cautious. the bearing prolly should be replaced but if ya can get it out with out damageing it your good to use it ya have to take it out to change the seal.
have ya cheaked with works directly every one i have called wanted to jew me i opened them up if ya get that parts from works their pretty simple on the inside and maybe ask around for some instructions.
elevation? seems like a big pilot for stock carbs but that could just be me? have ya tried playing with the air screw that will change your idle and if it wont your on the wrong pilot. someone correct me if im wrong i just put boyesen reeds in mine and a stock pilot (25) airscrew 1 and 1/2 turns out
when i got my bike it sat for a year and comp was at 90 after riding it for four hours went up to 130 sometimes ya get luck and the rings were just stuck to the piston and they reseat
i use the stock impeller and believe there's a reason their plastic. imagine if a metal one fails the carnage it can bring. i recently took apart one that had a billet on missing half the fins who knows where the shrapnel went. but my stockers been running strong for 11 years.