Great info.
I never thought about checking the tech section, shame on me

Update: For better or worse, shooting the speedo full of PB Blaster seems to have quieted the beast, atleast for the time being. I don't have to tell y'all what a pita it is to R&R the speedo, so I'm going to make a tactical decision and let it ride for now....
It's pretty stable upto 40 mph, above that it starts wavering, perhaps 2 to 3 mph. I ran it up to 60 just for a short time to check it against my gps and it was close enough. I just avg'ed inbetween the higher & lower needle deflections.
This is the speedo I got in my big trade, it's out of a 50 3100. The only difference I could tell is the high beam indicater is white instead of blue and the needle (whats left of it) in my 49 was red while the 50 was white.
I can opt to either try to rebuild my original or have it done, i'll ponder on that.
Thanks for the info
Dave.