There's no real rocket science involved in this one
I had all the parts shot blasted, using quite a coarse shot, then sprayed them with PJ1 satin black engine case paint.
The coarse shot gives the alloy a rough finish, and IMO, really sets the cases off. The only techy bit here is that it's increased the surface area and with the black paint helps radiate more heat off the motor
When the parts are blasted, i left any seals and inspection glasses in place to mask the machined surfaces. Also fit old screws into any exposed treads.
Make sure the water pump is extremely well masked around the pipe outlets else you'll be replacing the internal seal like I had to
I've also painted the cam belt covers black, which also sets the motor off.
Use all fresh stainless screws in the cases and you end up with a really nice looking lump