However, I neglected to share a useful thing I made.
The Ascension of the Magdalene gives a conversion statistic for Venetian ducats to D&D gp. I also found a reference document converting the various currencies found in 1632. (That document also relates old currency to modern United States dollars.)
Since all statistics indicate that early modern British pounds, shillings, and pence are roughly equivalent to Warhammer's gold crowns, silver shillings, and copper pennies, I also put those in the conversion.
Using all these statistics, I made a chart that converts Venetian ducats, Dutch lions, Dutch guilders, Dutch stuivers, gp (with a separate entry for the extremely valuable gold pieces in LotFP), sp, cp, WFRP gc, WFRP s, WFRP p, and modern USD.
Hopefully this is useful to you. View the "1610 UA Currency Chart."