Latest trial:
I'm thinking due to boiler overhang the O81 curve might be a bit too much and not allow for clearance to the walls and other tracks. I'm going to continue tweaking and see what I can make work. I've used on the wall side of the layout a decreasing radius to buy a few inches to the wall. I'm interested if anyone has tried this with success. I figure the boiler overhang would be greatest in the least commonly viewed angles of the layout.