Thought I'd post a new one here to mention what I did to fix the issue...
I ended up talking to Neil from Coal-Trol, who gave me some ideas. Among them, we decided to try moving the thermostat to a different location, more central to the room, and out from 'behind' the air blast. With that move alone, the temps have come within' 3 degrees of each other, fluctuating from 74-77 now. I also move my Max down a lot, from the 85 I was running to 55. Min was at 8 the whole time. Now, after a couple days of just watching, I've seen the FR go up to settle in at a high 60's-ish area.. so, I bumped the Max to 58 and I'll see if that gets even closer to my set temp of 75 or not.
As an added bonus, I'm burning a LOT less coal. Sweet.
Another idea Neil had was that I had, in effect, a chimney effect with my central stairwell (open, all the way through three floors). He thought maybe the warm air would like to go up the big empty hole in the stairs, but was getting stuck by the cold air that was try to return to the basement. Thus, an air traffic jam! He thinks a few well places floor vents in the perimeter would help. I went out and installed one today for a test, here near my desk, and I'll report back later to mention if that makes any difference here in my immediate area. Anyone else have thoughts on this?