I posted a comment on the article on Wax Poetics regarding this. You can kind of piece the answer together based on what Scott had written on this message board.
Based on what he wrote, I think it would be more accurate to describe the system as an "RLA era" or "RLA inspired" system. The J-horns and some of the old active crossovers were definitely authentic RLA. The rest of it is likely off-the-shelf items pieced together by Scott himself, or stock items purchased via Richard or other vendors. I know there are/were a lot of off-the-shelf horn loaded Altec VOTTs for midbass, JBL bullet clusters, Crown PSA-2/D150/D75, etc., and I have no idea about mid-hi's. I bet there's newer gear in there that he never posted about before passing.
One tidbit I enjoyed from Scott's posts was his need for a "talkover" feature on his mixer
that he originally had Richard build for him into his Urei 1620. Later he had Al Fierstein of Acoustilog build an external one that plugged into the loop in/out.