Hi Manny,
I can only answer the 2nd question. You do not need a pass or membership to use the Oklahoma Research Center which is inside the Oklahoma History Center. I didn't know they had the Supplement to the ORs -- I was looking at their archive collections. Guess I'll have to go back!
I've only seen the Suppl to the ORs at the OU Library and only had a few minutes before closing time. Apparently they can be checked out at OU so a number of volumes were 'out'. I'll have to go back to the History Center and see what I can find!
Ken