Is there a clamp bolt or setscrew that's supposed to anchor it to the block? I've got a Snap-On accessory for a slide hammer that was intended to remove a stuck distributor, especially on the mid-50's Ford V-8's. It's just a fork-shaped piece that screws onto the end of a slide hammer shaft. Maybe an oldtime shop around your area might have one. Stuck dizzys were pretty common on those engines.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!