I have good news! I had been struggling for months to get my version 2.5 ROV to work. The homeplugs refused to connect, despite lots of help from folks on the forum. I got frustrated and put it away for the winter.
So this summer I decided to take another crack at it. I found a new tip in the forums about testing the homeplugs by connecting the ROV homeplug to my router and the topside one to my laptop. I fired up the ROV and there it was, the elusive center LED that I had been looking for. I could see the cockpit screen and everything. (No video, but one thing at a time, man!)
So then I put the cables back where they belonged, and I realized that HEY the center light came back on! And I could see the cockpit! Maybe all this time they just hadn’t been paired and couldn’t find each other.
So this is real progress. I currently have no video, but that might be due to my ham-handed attempt at splicing the camera cable. I will check out the forums for that. Thanks to everyone for your help, especially @Walt_Holm.