No, that's far from the only Grand Prix without a quick release rear. I've got a '72 in Red that was: a. Built by Gazelle in Holland and labeled as such on the seat tube between the front derailleur strap and the bottom bracket, and b. Not only had bolt on wheels front and rear, but the rear hub was a flip-flop hub, threaded on both sides. Just got the shock when going thru my pictures that I seem to have never photographed it.
Now, keep in mind that the '72 model year was when the American Bike Boom was ramping up at full speed, and at the shop we were desperate for just about anything in a quality 10-speed that we could get to sell. Schwinn's were sold 4-10 weeks in advance, Raleigh's ditto 4-6 weeks. The factory was desperate for enough bikes to ship to the dealers, and were pulling out all the stops. So there would be some 'slight variations' from catalog specs just to get bikes out. And a desperate American wannabe rider really wasn't going to be overly picky about how the bike he'd bought a month ago was going to be equipped. After all, if he decided it wasn't good enough for him, we'd happily sell it to the first person on the next shipment list, who suddenly had a bike this week, not four weeks from now. And bump the unsatisfied customer to the next available Grand Prix (aka, either the next shipment in 4 weeks if he was lucky, or two shipments - 8 weeks - later if he wasn't).
I think.
I say "I think" because this seems to be a regional thing within the Raleigh system. I worked for A.R. Adams Cycle in Erie, PA, and never saw a Raleigh Grand Prix of this vintage set up like this. Everything we got thru the shop came with factory-specified Normand hubs and quick releases, and any markings led one to believe that it was built in England. I got this bike since I moved to the Richmond area, and a good friend/regular riding partner/vintage bicycle collector for at least 15 years before I got the bug has seen quite a few of these. In fact, back in the late 80's/early 90's he'd pick them up for $5-10.00 and strip them expressly for the hub sets. Fixie mania was starting out on a very small scale back then, and he could pick up $15.00 or so for the hub sets alone.
So these Dutch built Raleigh's seemed to have been shipped to whatever regional facility that covered Virginia sales, while the region that covered western Pennsylvania got all their bikes from England.