Okay, we're off topic from what F6Rider was asking. But just for the H of it, I don't putt putt anywhere, anytime. I rarely shift 1-2 below 7500, consistently hit the on ramp in third at about 8K and when I'm pissin off an HD guy I'll rev to 9500 3rd and 4th. Still have 64K on my motor and zero/nada/squat oil use between 4000 mile changes. If ANY of my bikes burned a quart/month, I'd at least hone and re-ring if the cylinders miked to within .002 of factory and over bore if it was beyond. But, that's me. And the last time I asked a shop mechanic anything I was riding a f'ing moped and packing lunch to school in a paper bag. Try this on for size, my c5 'Vette has 8 cyclinders and about 80 times the Hp of the VN750, and it also doesn't burn a quart/month...never met a 'Vette owner that did burn oil unless the engine was fubar...so why would a 60Hp twin suck that much oil unless it was hurtin?
Now, back to F6Rider, another question comes to mind...you said it was smokin out the exhaust, found oil on the piston etc...did you notice if there was a large amount of oil in either or both of the air cleaners?? If you did, then it's a clear sign of excess blowby, and that's a ring problem without question whether there is cylinder scarring or not.
Also, even though you didn't see an "obvious" sign of gasket failure, it takes less than .005 inch seal loss in the VN750 to cause oil migration.
The big question is, how many times do you want to pull that motor from the frame, and how much can you spend right now? The problem is that you yanked the mill before taking a CR. That would tell a lot. Because if the CR was low, but the valves are solid (turn the head upside down and pour mineral spirits in the intake and exhaust ports, if it runs out then the valves are fubar) then it has to be the rings. Or the gasket. Or the stem seals. Point is, once the pumper is outta da frame, replace all that is within financial grasp. Or, Rinse. Lather Repeat. Personally, I hate the repeat option.