Does anyone know if you can buy new oil pump gears, or do you have to buy a whole new oil pump?  

If the oil pump is a separate unit, not built into the timing case or something, buy a new pump. You'll be glad you did.  

Whoops. Didn't notice it was a dry sump. Rebuild kit may be available.  

It's a Weaver Brothers 5-stage, and I've had trouble making contact with them.  The wear pattern on the gears is smooth and even, they just have some surface rust.  

The four scavenging stages should be more than enough, worn or not.  It's the high pressure stage that I'm worried about.

Currently, I'm setting up a drill motor test to see if the pump can supply adequate pressure at various speeds and loads.  If it can't, a smaller drive pulley may help to speed up the pump.