Removing engine pulley

Problem with oil getting into primary case on my Dreer Commando so I decided to replace the crankshaft seal (which I hope is standard Norton). Does anyone know if I will need a special puller to remove the engine pulley, I believe the belt is a Gates but I don't know who made the pulleys. I like to have things ready before dismantling anything so I'm off the road for the least amount of time!

Uncover the pulley to see what threaded holes are provided to afix puller as likely same as factory sprocket but do heat the snot out of the pulley before even bothering to rap on the puller, may just pop right off as the heat soaks in. Likely looks similar to belows and even more likely is the same drive as Ms Peel as it was sourced from Dreer in his end days, which implies entirely possible its a basic Haywood at heart.