^ I believe so, yes. I have a late '83 C series Deluxe with the Sports maple body, and indeed it has the old style coupling on the OFR. Also that '83 red Imp just offered by your same seller also had old style coupling.
Still a grail to me though. My first electric guitar was a 1985 Kramer Striker 100st in black with the non-angled banana head stock, and non locking Floyd Rose. It was my Red Rider BB Gun.
That's a cool sentiment, and I can totally relate. My first "real" guitar was an 84 Focus 1000 in black with the banana headstock. It was my grail and I loved that thing, even though at that time, Focus models were not yet appreciated and were considered sub-par by most guitar snobs, but along with one of those hot little Gallien Krueger stereo amps, I never needed anything else for years. Before I went back to grad school in '92, I sold them both I think for $150 to buy books.
Come to think of it, the OFR on that 84 Focus also had old style arm coupling.
There are guys on here who know way more about the history than me, but I think your theory of swapped coupling (or maybe whole bridge swapped out) seems likely.