Help: 1983 stingray

Hi Guys
Been a long time since i was here !
Hope all is well in the world of low enders. my much loved 83 ray is having tuning issues. Two of the pegs keep on slipping on me to the point that i can no longer gig it. Yes i have used proper amount of wraps and tried new strings.
Could you guys please give me some advise as to
1) can they be fixed
2) can i buy musicman replacements
3) if i have to another brand to replace them which brand do you suggest
I hate the thoughts of it not being original so i would love to fix them if possible.

cheers in advance guys

David