A bit more light on the workings of the tailstock--the pivot point/fulcrum causes the tailstock to move laterally when the vertical position shifts. I measured the lateral movement with a micron reading clock and it shifts 40-45 microns total. this gives a plus/minus range of about 20 microns, much easier to do than shifting the top table! Your point is taken about lifting the tailstock instead of sliding . A good friend, sadly no longer with us was a very experienced toolmaker. He bought a new Studer cylindrical grinder back in the 70.s and woe betide any of his employees slid the tailstock!!But doing some housekeeping on a grinder is always a good thing. Taking apart a tailstock periodically to get the grit out, and making it like it was when it was new, will keep it that way. My tailstock DID have petrified grease in it as well as a clock spring that's broken, Something hard to notice since there's another adjustable return spring, that returns the quill.
Good to hear you got it fixed. Your tailstock may NOT be as heavy as mine, but I installed a small electric crane directly above my grinder so I can easily remove the tailstock, and clean the table and bottom of the tailstock. It's amazing how much wear the flat machined bottom of the tailstocks can get worn, by continually SLIDING the tailstock. My original tailstock was badly worn. Now anytime my tailstock needs to be repositioned, I lift it up and clean everything. I NEVER slide the tailstock anymore. The tailstocks on my machines easily weighs 80 pounds or more. Since you have the swing down ID grinder attachment, you'll certainly want to make lifting off your tailstock easier.
I have five different Jones and Shipman Cylindrical grinders, but have never seen your model. My small grinders are 1311's. Yours is smaller yet. Looks clean!
From the paper work associated with my grinder it was supplied to a government facility in Canberra circa 1987, so it is probably the last iteration of the 1212E. I have another 1212E which is the previous iteration with the electrical box down low on the right hand side. This one was supplied by the Australian distributor who ceased operations in 1984 so presumably this one is pre 1984, but by how much i have no idea. Funnily enough, the serial # on it is much higher than that of the # on the more recent one. Would you know how the J& S numbering system goes?