Old but needed topic.
I have one of these, they are great little units and I need to do a CLA because of a huge dust bunny in the eye piece, however, I want to pass on some info for those who do no know where to get the bearings needed for camera repair.
Hitachi, on Amazon offers a small, metric assortment for, in 2020 -21, cost about $8-9 and it will have more than enough of the tiny bearing, for jobs like this.
I think there were as many of 80 each of the 2, 2.5, and 3mm balls, and IIRC, goes up to 8 or 9mm.
They also have SAE assortments for those who need them, in the same price range.
If you've Amazon Prime, then the prices should not rise with shipping but check to be sure.
Good Luck with your repairs and Thanks to Wolves 3012 for putting this up where We can find it.
Cheers.