My choice in N.A. is DigiKey.
There should be quite a few selections on their site.
If you notice, there is a black bar at one end, this is the ground or chassis connection end.
Looks like it may be a suppression cap.
M.
It's the base assembly for an Olympus phase contrast microscope. It was impressive when the capacitor let the smoke out of it. Scared the guy using the scope pretty good.
That capacitor type doesn't look particularly new to me. If you have a clear idea of its use, application, applied voltage, etc. there probably is a more reliable part to use.