I've updated the spreadsheets in my signature with the new PRT's and NPC cities/towns added with R31. The new island keep/castle lots within them are now added as well. Sheet 1 has Npc towns/cites Sheet 2 PRT's. If you find something I've missed please send me a pm and I can get fixed. Enjoy.
One thing i wonder is how many of the water village lots is costal. Been annoyed in the past on how many knights that places lighthouses in rivers so hopes they will make sure is lots where its logical for them to place lighthouses in to.
Thanks for this resource - is there any way to identify NPC layout type like you do with the PRT? Grassland, mountain etc?
Sotamap is a good place to look for layouts. The new ones from R31 don't seem to be updated there yet though.