Anyone know the size actuator I need to order for a replacement?

What's wrong with yours? There are several threads in this forum regarding servicing the actuators ... mine's been apart a coupe times.

It is slow and all scratched so I want to get a polished one. I know they can be rebuilt but I would rather replace it.

What gets rebuilt? Where do you get parts?

Mostly just disassemble and give it a good cleaning. The old grease gets hard and it's caked all over the gears which might be why it's slow.