Hello Rob i don't´have info about this. Lot of merchants were captured. And one ship of the line was stranded at the barbary coast , Fernando Vii in 1809.
I has been making the spanish flag on the ships from 1701 to 1785, may be you can put one of this flags on your ships. I am using this for battles before 1785
Name: Spanish Flags 1701-1785.jpg Views: 8492 Size: 201.5 KB

I have the pdf if you prefer. Regards