Genoan Grosso (1466-1476)

Nice pick-up austrokiwi! I agree with your description and orientation. Obv is castle with snake, surrounded by G S DUX MENDIOLA D IAN. Rev is cross surrounded by + CONRAD REX ROMANO P. I would attribute it as Biaggi 943. It was minted under the authority of Galeazzo Maria Sforza.

There is a very interesting read on him on wikipedia:

https://en.wikipedia.org/wiki/Galea...Maria_Sforza

"Monete e Zecche Medievali Italiane Dal Sec. VIII al Sec. XV", by Elio Biaggi. This book was published in 1992 by Monenegro SAS. It is written all in Italian and the prices are in "heavy" Lire. Biaggi's book is impossible to find at any semblance of a reasonable price. I looked for the better part of a decade before finally purchasing mine early last year.

IMHO, your only alternative to Biaggi for complete coverage of medieval Italian coins is Corpus Nummorum Italicorum (CNI), which is 20 volumes published in the range of 1910 to 1943 (and then re-printed in 1961). I've never seen a full set of those for sale, but they would be well beyond my book budget in any case--maybe the cost of a decent used car?!

If you are committing to collecting Italian medieval coins and want to have the reference materials in hand while purchasing coins, save up your money and your patience because you are embarking on a long and costly trip to find that reference work. On the other hand, I am quite happy to provide as much info as I can from reading my copy--just keep posting here in CCF!