I'd leave it alone as well.
The front could possibly take a light surface cleaning, but the back would be damaged by most attempts since the cardboard is porous. The fronts are coated for printing, but the backs aren't.
Once cleaned on the front you'd have a mismatch between front and back that would look odd.
Here's about as far as a light surface cleaning can get.
Before, grubby front from probably decades in a paper bag in an attic. With another card on top of about half of it. But the back was very clean. (SC 350-460 F25)
After, Just a light cleaning with water and a q-tip. I thought I might have wrecked it, but the light area on the neck is the actual color. I should have done a bit more, but I stopped and didn't compare it to online scans.
The surface still holds some dirt in the usually invisible cracks in the surface coating.
And yes, I was very surprised at the grade. I'd hoped for a 40.
And no, I'm not cracking it out to finish the cleaning. I don't think it would benefit much, and going further is both risky and borderline inappropriate.
Steve B
