Sounds too specialized. Will have to take them somewhere.
If they went to be powder coated, maybe black, would the powdercoater prepare them first to get the final smooth finish?
It's patina; leave it as is to show you are a real battle scared adventurer.
Protection in depth eh? How about a length of 40mm hose over the top to protect the crash bar protector? Then you’d have cylinder heads protected by cylinder head protectors protected by crash bars that are themselves protected by crash bar protectors that are in turn protected by crash bar protector, protectors.This is what I’ve done, it’s silicone rubber tube off eBay and a couple of tie wraps.
Most bike falls are in a car park or similar and this cheap bit of rubber will absorb some shock and save you getting out the steel wool and wet and dry paper.
Function before fashion, after all they are ‘Crash bars’.
Ebay..search..
25mm - 1 Inch Silicone Hose Straight Joiner Coupler Coupling Pipe Connector