No I've got it. It's the right part. I need to send it to Raxles to get it assembled with the outer shaft. I have the cup and all the other parts for cores. Jamie brought this to me the day someone side-swiped his Mirage.

The part came with a Japanese newspaper in the box. Think it's JDM? I don't know why I rambled about the jackshaft earlier, because I've seen them on tons of cars and haven't paid attention. Lots of FWD cars just have a long and a short axle, but plenty of Hondas have them, too. When I get this back from Raxles, I will have equal-length half-shafts on the outer joints.
YouTube resolution is crap so I thought I'd post a couple shots of the finished mounts.
The reason there are no gussets on the rear mounts are numerous. The 2" box steel crossbar is 4x as thick as what was there before, the rear is mounted on a flexible "boomerang" that absorbs lateral shock, the 2" piece is welded to a larger plate on the end before the frame rails, and any twisting of the rear is absorbed by the rubber bushings in the mounts. Anyway, you can see where the frame rail was welded back together where I cut out the trunk area (the long welds). I'm getting a lot better with the MIG and learning some new techniques. After I had that tacked back together, I added a continuous bead for filler and strength and ran that into the top of the plates on the crossbar. It was just spot-welded sheetmetal before.
The welds on these look terrible, but these things aren't coming off. I globbed the final welds on there. There are multiple layers on all sides, and where the box steel was welded to the frame rails, endplates were added. And where they meet the frame rail, I filled the endplates over the previous welds and double welded the endplates to the frame rails. The 5/8" bolt head is welded to the inside of the box steel.