Cadet 75 need parts information

[mastercraftka]

I have my grandfathers old Cadet 75 it is a rear engine that has briggs engine and I am trying to swap it out with another but can not get the drive pulley off the crank shaft. Any ideas where I could look for a replacement?

 

[rcbe]

if can remove the engine from the mower with the pulley still on, would take it to a local small engine shop and pay them to remove the pulley for use on the replacement engine. Less cost that way, IMHO...
for a pulley part #, might poke around here: Lawn Mower Parts, Small Engine Parts & Much More! | PartsTree.com - Briggs, MTD, Toro, Cub Cadet, Husqvarna, Troy-bilt...