How do you touch up parkerized parts?

[mutt]

My castle nut got a bit marred when I took it off. Nothing serious but there's a few bright nicks I'd like to cover up. Is there a paint that's a good match and somewhat durable?

[BPTactical]

My castle nut got a bit marred when I took it off. Nothing serious but there's a few bright nicks I'd like to cover up. Is there a paint that's a good match and somewhat durable?
Get ya a touch up blueing pen-Birchwood Casey makes one.
Degrease-dab the pen-oil.
Good as new!

It wont be quite as durable as the parking but unless you feel like re-parking it that is about it.

[mutt]

Cool. Thanks for the info!

[Quib]

I like to use G96 Cold Blue. It matches really close to the parked surfaces I've applied it to.