Call Mark Jorgensen ( 1-800-889-1893) or email at mjorgensen@woodhouse.com. I know he has redone quite a few that seem to have burned off a bit of said paint and not sure what he used, but sure he can give you an idea.
Just a satin black, you could use maybe a grill type black, but unless your tips drop down behind the sill and burn it directly it will be fine with normal paints.
I re-did mine with satin black BBQ grill paint. Been about 2 yrs now, still looks good. Was pretty easy to mask off the old area, give it a light scuff with 3M Scotchbrite pad, cleaned and painted.