Vintage Fan Capacitor Replace

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So I recently got my hands on this beautiful Mitsubishi fan, oiled and it runs smoother than any brand new fan I've had.

My problem is I found the capacitor was from the 60s and knew it'd need replacing (had a cap from 53 do this in a sewing machine already) so I pulled 2 caps from (within 5 years) old fans. Installed 2 in parallel to give the 2uf rating.

Problem is when I was done the fan would barely spin, thought it was because they were in parallel but I cut one out and it got worse.

Had to reinstall the old cap for now but don't feel comfortable leaving it on alone, bought it for white noise when I sleep but don't trust it.

I assume theirs something I'm missing about the capacitor type or something? The replacement caps were rated 1uf each and were similar voltage ratings, (small black square caps out of somet cheap fans). One cap was from a working (but just damaged) fan so the replacements should of been fine.

I assume this cap isn't safe to keep using or is it some special kind? Where would I find a genuine replacement that'd work if/when I do replace it while avoiding knockoffs?

Thanks to anyone for any help.