Hesse-Cassel - an uncatalogued year/initial set

I have what appears to be Hesse-Cassel, 2 albus, 1770 BB. KM 511.  All reference I can find shows only 1770 BR.  Can anyone share a link that shows this is catalogued somewhere?  

Maybe a die break (but it looks to clean and follows too well) or someone f***ed up the cut or recut of the die. You can sill see the end of the right down stroke of R on the lower right of B.

P.S. please always provide links to what you think is you coin, it saves time especially with the search and database issues we have now.

so here is the link that started this little die/mm issue:  https://www.ngccoin.com/price-guide/world/german-states-hesse-cassel-2-albus-km-511-1768-1783-cuid-1146812-duid-1368744

NGC shows a KM# 511; 2 albus 1770 BR.  My coin looks like 1770 BB.  My initial hypothesis is that this is die wear/damage.  I isolated and made into B&W because that helps me at times see what is truly going on without the interference of color.

Numista listing N#38691 , does not list a 1770 2 albus at all unless I cant pull it up in my search(which is possible) even though NGC does have the date.

also; in Standard Catalog of world coins 7th edition page 446.  the coin is listed as KM# 511  2 Albus 1770-BR.

So, I am supposing that my coin is a 1770 BR with a die break making it appear as a BB.

Anyone have any thoughts?

My guess is contemporary counterfeit, looks like brass with silver wash