ho-downer

I recently purchased a nice 1972 ZF Fairlane which has a 351 cleveland in which the Distributor is corroded in place.By that I mean that is it impossible to take it out of the block.I have tried soaking in the usual gear like Rostoff,Rp7 etc, also have tried lighly tapping to try and turn it hoping to break the seal all to no avail.(Just keep breaking small pieces of the collar)
The timing is out to buggery.
is there a sensible solution as to how to get the bugger out without breaking it ? If Not and i snap it off can I still pull it out without anything dropping into the motor?
Cheers
Ho-downer