Used to paint a lot of these type of old watercolours back in the 1990s for a gallery in Bradford Yorkshire.  The owner of the gallery must have had a lot of contacts as , as soon as I dropped them of they were not seen again, at least by me anyway. They were painted on a good quality watercolour paper 9 ( A4 ) size so quite small but they paid around £50 mark , I painted 4 per week so quite a nice payout. 

This painting is after 18th Century watercolour artist John Varley OSW.