Thanks for the response.
Luckily, the vendor who sold me the wrong model is making good on the mislabeling and is issuing a refund. I have a Rowe repair guy who will fix the 50-watt stock amp for $150 + shipping, but it's going to take some time and I want to keep my jukebox up and running while the original is out (and have a backup amp for down the road as it gets harder and harder to find spares or people to fix things). I found a 125 watt Rowe amp with the correct Molex connectors from (IIRC) an R86. It's P/N 6-07438-04. Not the 130-watt one, but will work from what I understand. Once it gets here and I get it set up, I'll send the original 50-watt out for repair and put it back in the machine when it comes back.
Meanwhile, I'm enjoying my RI-5 even though only the left channel is functioning. I purchased a stylus tracking gauge and set the tracking force properly (it was all the way up at 5.8 grams!!!!) so that my 45s don't wear out prematurely, checked the condition of the belts, put a new stylus in (it came with two unopened spares as well as an unopened spare cartridge), and gave it a good once-over cleaning. Once the amp comes back from repair, I'll have the local coin-op specialist come out and shop it just to make sure everything is in as good a condition as can be expected. The wife is even finally coming around to it. I found some great 80's 45s in near mint condition at the local antique mall the other day, so I'm slowly but surely changing out the play list.
Thanks again for the reply! Glad to know there's somewhere to turn online for this kind of stuff.