That is definitely a Kawasaki drive clutch in your pictures.
The 1st picture below is from a 1981 Drifter parts manual showing the attachment bolt with a single lockwasher.
The 2nd pic shows a 1979 Invader diagram that used 3 spring washers and a shouldered washer...same clutch, though.
You have the correct Kawasaki puller it looks like in your 1st pic.
Once you remove the attachment bolt and washer(s) there should be a large hole that the puller will easily fit through.
I don't understand what that rusty looking chunk of steel is that your puller is sticking into.....don't underestimate what a previous owner might have rigged up...
That shouldn't be there..