vintage peugeot uo-18 headset problems

[liang]

hi everyone!

i currently have a vintage peugeot uo-18, and i think the ball bearings in the headset are loose because my fork is wobbling! i'm fairly new to fixing vintage bikes (it was even very difficult to find the correctly threaded bottom bracket for this frame!) and was wondering if i would need a rare sort of headset that wouldn't be offered at my LBS? should i try to find an actual vintage shop near my area?

ALSO!
I'm thinking of powdercoating the frame - but getting the bottom bracket in was so difficult, that the maintenance guy said it'd probably never come out again. do you think it'd be okay to leave the bb in while powdercoating?