Hi Max,
that pulley would do the job just need to bore it to suit the PT blade boss. Same problem with the full crank motors I don't have any spare pulleys for those either
Maybe I can use these pulleys and press them down to make them into an "M" section pulley. I guess the only way I will find out is to get a few and try
https://www.ebay.com.au/itm/313064890971