This a particularly poor example of a
large type. It is rusty, dirty, and has solder tags and
other parts screwed to it. Note also that it has a 3/8
spindle but even that problem can be overcome.
So, remove all the bits and pieces first, and check the
vanes are not bent and are evenly spaced.
Place the capacitor in some warm soapy
water. Use a scrubbing brush on the end plates, and a
soft paint brush to carefully clean between the vanes.
Remove any flux residues.