Very helpful many thanks! Don.You may want to check out the RE Owners Forum (royalenfieldowners.com). Look at the Classics section and someone there has fitted an analogue tacho on the Classic in the location the Tripper GPS would be. The photo look quite smart.
As for the gear position indication, I've not seen anything. I'm quite happy to just have neutral indication and rely on engine noise/speed to decide when to change gear.