I just "fixed" the sticky shutters on two of my old cameras and was surprised at how easy it was. A Brownie Six-20 and Argoflex 75 ... admittedly not the most complex mechanisms or involved repairs. Just flooded the mechanism with lighter fluid and fired them over and over.

So I'm wondering if some of my other cameras would be receptive to similar treatment. But they have more complex things going (ie self-timers) so I'm a little apprehensive.

Nettar 515 that sticks if I shoot 1/30 or slower.
Yashica 635 that got wonky when I tried the timer lever. And when I cock the shutter, its lever needs a little nudge to snap back. But otherwise seems to fire ok (I'm waiting for my first roll to come back.)
And a Kodak Retina IIa that seems to stick when I set it at 1/500.