Yes, either that or I could buy it, use it then re-ebay it- which is far more likely to be successful that using my limited soldering skills to make one. Agree about not really needing a dyno, by the looks of the one pictured on ebay (which seems to pre-date the vee anyway though) it doesn't need to be plugged into the mains so you could easily do a roadside trial and error approach - or maybe even tape it somewhere suitable and try the adjusting whilst riding.
Mine's definitely at the weaker end of the scale, 52-58mpg at speed and spotless plugs and exhaust. I'll keep an eye out for a s/h PC3 too, though all these approaches seem a bit of a sledgehammer to crack a nut, I will check out the local Suzuki dealer too just in case they have a box ....