And the solution that worked is.... (and one that didn't). Thanks for all the ideas.
Strap wrench I bought to open jars - well, I broke the plastic handle when I added a pipe to create more leverage. Does Kobalt have a lifetime guarantee on their hand tools? The rubber strap provided great grip, but alas did not allow impact to be transferred easily (band stretches and absorb the impact).
What did work : I removed work piece (platter) - albeit with a bit of difficulty. The screws on this 3 or 4" faceplate were about at the same diameter as the edge of the headstock - so getting tooling in there required just the right combo of tools. See pic.
I used a ratcheting wrench and a short bit from a bit set to access - somewhat difficult to see, but you can make it out there.
Then I replaced work piece with a 2x4 approx 3' long - what is actually shown in the picture. Not easy to insert screws in SYP without being able to pre-drill holes or put much pressure on the bit. Eventually I used a metal plate to put pressure on the end of the bit until the threads started to grab.
Then after locking the head stock, a quick rap on this 2x4 loosened the face plate.
I believe the barrel (threaded portion) of the face plate is not quite as long as the Nova I have, and there it does not seat on the existing washer that was in place - I think the threads simply bottomed out.
I will use a thicker washer when I use this face plate, and I have filed two small opposing flats onto 'the barrel' in case this happens again. Thankfully it is Al so filing those was not difficult. BTW the clearance did not allow any of my several pipe wrenches to fit in the gap. and the outer ring was too large too grip.
Again I appreciate the assistance.
Back to turning.