if it is stock oil pump, those are hard to come by... may get lucky and find a good one from someone
you can make a new screen & support, buy new brass screen and make a new 'filter' and you can braze/ solder it to the cup part and if needed put on new heavy screen 3/16 spacing or so to hold the form. use a small ball that fits in the cup to shape it.
attached is a shot of the one i have
here is a previous post from Chipper on redoing the screens:
There are many possible ways to duplicate the half ball shape.
Best is find a rigid, solid ball (croquet anyone) that is about the right diameter. With good gloves and a small hammer, push, tap the hardware cloth into the desired shape. It will wrinkle and bunch up places so you may have to either bend individual wires or clip them so they conform to the desired shape. Once in the general shape you will need to trim the open edge to fit the solid screen base. Then crimp, solder or tack weld the half ball in place. If the inner screen is damaged you might have to replace it as well. It should be a little easier to shape but you will end up with creases as the wire is forced into smaller shape. That is okay as long as the screen remains intact without holes. A few overlaps will not reduce oil flow enough to be a problem. Sealing to the base can be a bit tricky but careful soldering or crimping can minimize places where crud can bypass the screen.
A little more complicated method is to push the flat screen into a pipe with the correct (or nearly correct, smaller is better than larger) ID. Just remember that you will be expanding the screen openings so you have to start with screen with smaller original opening.
The best is to find or make two molds or dies (male & female). Then using a press squeeze the wire between the two to get the desired shape.
There are others as well.
link to the discussion: https://vccachat.org/ubbthreads.php/ubb/showflat/Number/413225