Thank you both for the recommendations. The bottom two screws of the doser were very loose so the ratchet and the paddle didn't meet all the time--pulling the paddle only occasionally moved the doser vanes.
The grinder was given to me after it was taken out of service from a commercial setting over a year ago as it appears the doser stopped working for the reason above. The doser is pretty beat up but once the screws are tight, it works fine albeit very dirty with old grinds. The inside underside of the doser where the brass cog is has as much coffee grinds stuck to the grease as the doser itself, probably because the two screws have been loose for a long time allowing grinds to fly up into the grease.
It's my next rebuild project.
I have to order new burrs from Chris so I'll order some grease as well. The grinder appeared at my doorstep (a gift from a good friend) a day after my Vario arrived from Chris, strange coincidence. I've got the Linea working and didn't have a grinder, and now I've got two. I really can't wait to get the SJ cleaned so I can compare shots from both.