After googling for background info for the project - and finding some helpful but incomplete references in ADV, UKGSers, and the Pelican forum - I decided to do as much as possible to fully document the process for interested R1150** (and R1100S) owners.
The final step is the speedometer signal circuit for bikes like mine with speed signal derived from ABS Hall sensor. You mentioned in your post an actual oscilloscope measurement of the signal... do you remember offhand the specifics for the signal? Vdc amplitude? Ground-referenced or other? Anything you might recall would be helpful.