I was in just this same dilemma last week! I picked up an unlaced Maxicar hub with a Suntour NW freewheel. iBOB discussion
here.
Basically the biggest recommendation was to re-lace the drive-side of the wheel, even just crudely, into a rim. In my case, this would have required removing the cogs since the large cog obstructed the spoke holes from getting fed spokes.
In the end, I removed the cogs, but instead of lacing the wheel I filed a channel across the inner freewheel body using a dremel with variously sized cutoff wheels, taking great care to avoid grinding into the hub threads or any other part of the hub, then "cracked" the freewheel body open with a cold chisel. Once cracked, the diameter of the body's threads increases slightly so the threads dissociate from the hub threads. I was then able to just spin it off by hand. You can see in the pics how close I came to the hub threads without actually touching them, and you can see the cracks from forcing it open with the chisel. It was like playing Operation when I was a kid! (Only the stakes were higher).
EDIT to add: after getting the cogs off, I first tried immobilizing the hub on a large block of wood using a handful of spokes laced into the hub and passing through small holes in the block, then bent 90 degrees so they sat flat against the underside of the block, and clamped them there, but no go... the torque on the freewheel body just pulled the spokes right out of the block like spaghetti!
