I wouldn't want to ruin the powder coat on the outside though Jonners!!

I'm blown away by the comments, thanks guys, it's really spurring me on.
Mart - This is the satin black paint I used for the back axle or anywhere that requires a satin finish really.
https://www.tetrosyl.com/tetconnect/pai ... ts/ATS013-
It covers really well, sticks to virtually any properly prepared surface, dries hard and has a fan nozzle on it oh and it's cheap! I got a case of 12 from eBay seller wmfltd2012 for £39.99 delivered, works out at £3.33 a can. Not sure about the anodising yet, I haven't had a chance to find out.
Superb!!Can someone tell me how the axles left the factory, were all of the bolt heads painted over or left bright?
If you're shooting for factory finish you are way off target. I've just checked my NOS sprint axle, I'm afraid you need to strip that paint off again. Then, apply one coat of paint to about 80% of the surface. Use something thick, gloopy & hard to spread such as smoothrite having left the tin open for a month using as brush a lively spaniel. Be sure you apply enough paint to get a good selection of curtains and runs. Leave the remaining 20% unprotected.
But to answer your original question they were painted complete. It's hard to tell on the bolts specifically due to the years of dirt on mine but there are clear signs of paint on the tab washers and even on the plastic bungs in the brake cylinders.

Pippin - Thanks, I think I just have OCD! This is one of my spanner drawers...

