Didn't get any feedback on this one but thought I'd share the outcome of some homework and my attempt at breaking things free. After doing some staring at the service manual cutaway of the clutch I came to the conclusion that the clutch disk was rusted to the flywheel. There's a lot of surface area there to break free via shear force but decided to give it a try. Hooked her up to my 4320 with a couple of 6ft slings. The plans was to pull the 1010 and push in the clutch pedal and hit the brakes hard to try to break the rusted surfaces. No luck. The tires would just drag on the ground. Next I headed for the pavement. Went about 200 yards in one direction and tried regularly to trounce on the brakes with the clutch pedal depressed. Didn't work. Locked up tires would just skid on the pavement. Headed back the other way continuing to hit the brakes with the clutch pedal in and just before we got to the driveway, IT BROKE FREE! Turned on the key, let out the clutch, started her up and everything was working fine. Backed into the barn using that good ole clutch! So pleased that I got it free without having to split the frame. No more outdoor storage now that I have a barn!
One last piece of info to share. That weep hole that I was hoping for in the bottom of the frame below the flywheel does exist. It had been painted over. Cleaned it out; small amount of water came out. I then opened up the throwout bearing grease access port on one side, the timing port on the other, and set up a heat gun blowing warm air into the housing. Left that in place for a couple of hours and when checked with a flashlight, everything inside was dry again. I had also clamped the clutch pedal in the depressed position while drying things out.
Hope some of this is useful to someone in the future.