I just picked up the latest Spinks books from eBay for about $30. Not too bad if you’re taking a look.
I could see that 1915 florin as an MS62. That is mainly bag contact as opposed to wear. I think that even in Merrie Olde Englande that this would merit very close to a "Good Extremely Fine" grade. In my experience, this is slightly scarcer than the other war years and obviously is of good sterling (not that pot-metal 0.500 cr--). The 1925 a F15 grade IMO.