Rating System Fails This Coin, Maximianus Follis, 85% Surface EF

I agree the red encrustation is a bit of a put off but its still a nice coin..
Even if you did or could remove it without damaging the coin it looks as if this area of the strike is quite flat and probably wont show much detail anyhow..

PS..Its still a shame I cant buy from you

"Very Fine or better in terms of wear, uneven strike, brown surfaces, adhesions".

I disagree
One key factor in grading an ancient coin involves the 'competition'
With extreme rarities allowances can be made for the fact that the owner is quite lucky to even have one in any condition !
In this case we have a type that was produced in great quantity and is commonly found in large hordes
The empire at this time (tetrarchy) was a solidly top heavy military dictatorship with vast sums of high quality folles being issued
to pay the enormous military maintained by four full time emperors
For me to grade this type as EF or near
I expect three things
I expect to see good silvering
I also expect to see some luster remaining in the fields with little evidence of wear on any of the high points

But that's not what I see
I know I probably sound mean and harsh about this
But I own nearly a hundred of these types (around 50% London - 25% Trier & Lyon)
There are quite a few folles in EF+ yet to be found
Buried long ago by pensioned veterans of living out their retirements in the vineyards of Gaul