Sorry - not putting down your need for a farkle. I've seen gear indicators and thought they looked good, but decided against. At 6'4" I have an issue with the amount that I have to move my head in order to look down to see things on the dash. Its not the head movement that is the issue - its the time it takes to change the focus back to the road. Its a fraction of a second, but it is more than the quick glance that is needed for the speedo directly in front. So I rarely use my tachometer, even though it was one of the things that 'I must have' in a car and on a bike. I don't use it nearly as much as I thought that I would. I cannot see the dash indicator / winker lights for example - the hood obscures them from where I sit, so a more important farkle for me has been LED strips across the bottom of the mirrors.
Anyhow, I'm on the PC again now, so I dug out a couple of photos of powerlet sockets fitted. Click the thumbnail to enlarge.
Front Right. This is taken from my older ST1300A6. I had to fit it on the right, as my Honda heated bar controller pushbutton block was mounted on the left side. It was a bit of a pain on the right, as it was not easy to unplug - hence the relay microswitch.
Rear Right
I had to be careful with this one that I could actually get to secure it with the locknut from the inside. It's a bit of a fiddle, but possible. On my present ST1300, I took the rear cowl off to fit it. The second photo just about shows the underneath of the plug on the other side of the tubular frame.