A little update - I took a bit of flitz to the receiver last night and this morning. I found it not nearly as "dangerous" as I anticipated. That's not to say I would ever use it without extreme caution. The major freckling came out with a couple light passes - it definitely brightened up the receiver with most of the brownish patina remaining. I even found some very faint case coloring hiding in a few protected areas.
Sun was shining today - so it appears brighter than it actually is. That's the only cleaning I plan on doing - she shall remain as is currently.
