AN Ian the info you have put here is from the graph what i see is about right 45 mm dia an 4mm shaft an pitch 46.1 so i'll try an order these from cornwall model boats an just hope that they will do the job ps if i try an order from this company i may incurr customs feeTry here.
https://raboeschmodels.com/product/148-5-blade-metric/#iLightbox
45mm brass 46.1 pitch. only 4mm shaft though. About £21 each.
cheers chrisb