Re: how not to treat a Mark I
Both of my Mk II's are D/T'd for scope mounts from the factory. Perhaps this one is as well?
I'd try a file/sandpaper to clean it up as much as possible, then rough grit blast it and park it.
Or, if you want something more refined looking get high temp JB weld (the stuff they claim can go on an engine block) and fill/sand the pits. Then coat it with duracoat, cerakote, teflon, etc. and bake it on
After that, it will disappear.