Won't fit; the cam wheels are too close together.
You should be able to get seals from any good bearing house. Nothing special about the seals used in Ohlins forks (at least not in the R&T's). If they can't supply them, Steen Hansen's are the Canadian Distributors 1-800-661-9498.

The harmonic tensioner works with the Mathesis. It's pretty expensive.
It's also next to impossible to get repeatable results from the device. Set the tension to obtain the required frequency, spin the motor a few revolutions and you'll get an entirely different result. Somewhat like tuning a guitar with rubber strings.
I have an SPX meter. It looks pretty trick in the tool chest but I set belt tension by feel alone. Done a bunch over the years and have never had any problem.