Mr T, well it is cleaned now :) I wanted to see how cleaning would go and as it was not worth much and I did not know what that marking was made from... I now think it is some kind of glue.
The coin came off
ebay with a 1943 florin (that I wanted), some threepence's, some penny (one side panted gold - now in the bin)and some world coins - so in all $11 for what I call a 1943 in VF, I am happy to play with the 1915HP