Old Salisbury Clutch, Is there not a center bolt ? IF not , remove the three bolts and bell.
Salisbury is well known for the clutch being all Aluminum, other than the springs / arms , etc.
They molded the main part to a steel tapered shank. The only real Correct way to remove it is with a clutch puller bolt.
It threads to the inner thread of the clutch shaft.
Heat is your best friend, heating the inner half of the clutch will expand the steel shank from the crankshaft.
Best of luck, I have had very little luck when it comes to pulling this particular clutch.
Don't Hit this clutch like ithis " Video " The Salisbury will not stand up to it.
https://www.youtube.com/watch?v=LZ7Pt29izPc&feature=player_embedded