Yes, if you have "1441" for the "W" number at the bottom of the speedometer face, then that definitely is from an R45 (meant to go with 35/9 final drive, which was only factory installed on the R45 35HP model).
It is *possible* that someone may have used the speedometer, but adjusted the internal gearing for it to operate with a different calibration - but doing this without changing the face would be very unusual - to recalibrate the internal workings is not cheap, and if one were to go to that effort, spending a little more to replace the face of the speedometer to reflect the new "W" number would be expected.
You want to look at the silver/gray final drive unit (cardan drive) on your motorcycle (I don't know the year of your bike). Toward the top surface, near where it is bolted onto the black painted swingarm which encloses the driveshaft, you should see a numeric ratio stamped into the silver metal. It will be something like "32/9" or "31/9" as those were the standard ratios used on the R65 models (though as you may know, these things are interchangeable among different airheads, so may have been swapped). Let us know what you find and we can tell you what speedometer ratio you should be looking for. As it is, unless you have a "35/9" final drive on there already, your odometer and speedometer readings are quite a bit in error. If you do have a 35/9 final drive on there, you'll have great acceleration, but a much lower top speed and buzzier cruising as the R65 power plant has considerably more usable power and can use the taller gearsets.
