Hey Bach Man!
Years ago (many!), we were told the best match for the graphite on the Annie smokeboxes (and other engines) was Krylon ColorWorks MS 769 anodized bronze. It seems Krylon doesn't make that anymore. Is there an equivalent to use? There's a Dark Metal in their inventory. What are you using now?
Railroad Pony
Right now I try to find a close match at the auto parts store.
Plasti-cote (sp?) seems to work well...
Have fun!
the Bach-man
Fortunately, I still have most of a can of it.