Sonnet's cable is stupid long and needs all the help it can get over its excessive length. Sonnet only ever made low profile 6100 form factor accelerators, hence the fancy, active component cable.
Also the PDS flatflex cabling only allows you to use the HPV card while the Sonnet processor is in the PDS slot. All it does is save the need to get a NuBus card. And while these are becoming pricey anyway, I find that for gaming any card that can give me 1024x768 @256 colours is more than enough. The HPV is a good card but it's not that much better. It might help avoid flooding the NuBus-90 bus though.
If you test the low end PDS Video Capture card against any NuBus card the metrics will prove it blows the doors off any NuBus Card, accelerated or not. HPV 1/2 allows higher resolutions at built in video speeds. HPV 2/4 is the bombe in 4MB configuration, that much VRAM allows far higher resolutions. Was any 68K Mac upgradable to 4MB VRAM?
Last I looked A/V and HPV 1/2 were very reasonably priced and well worth the NuBus slot their dummy connector occupies in terms of performance. I only have one Nubus card that can push that many pixels, even supporting 1600x1200 with its 6MB of VRAM. When a seller knows what they're listing, HPV 2/4 commands a premium. 2/4 was the stock board in the high end 8100 config IIRC.
I have both the cable and the processor from Sonnet and I'll take pictures of them for you but I'm not sure how much they will help. I would very happy if you made them available for sale to the general NuBus-mac owning market. There is surely a small but steady market for these.
Sonnet G3 Cards usually run at a higher clock rate than the NewerTech variety and so command a higher price.
NewerTech's Accelerators have seemed to be available at much lower pricing levels in the full height, attached passthru cable configuration. Most, if not all of the several cables I have work, but they're reported to develop problems if roughly handled. The two that "don't work" would be due to Accelerator problems AFAIK. They induce a PSU "click/clunk" and fail to boot IIRC.
Love my Sonnet kits, but cables, especially in full kit bundles are pricey. But as I think I'd agreed upthread, building the carrier for dummy NuBus slot positioning would pose no real problems if the cable is available.
@Simon_Bitdiddle Pursuing the NewerTech option could cost you much less than what you could recoup by selling your Sonnet. That's low hanging fruit in the PDS/dummy NuBus Slot passthru game.
As I offered upthread, I've got working and non-working units to put out on loan to a competent 3D printing/PCB development type. If the Accelerator can be brought back to life I wouldn't expect to get it back. Lets call that a carrot on the end of a meter long chip puller.
The adapter might be configured to support both Sonnet and NewerTech cables.
On a side note, if anyone has the Big Metal Can from Radius, available overhead cubic allows for either adapter for passthru PDS video to be installed without tying up a NuBus slot. The Radius 81/110 was the cream of the crop in the NuBus architecture PPC era.