I forgot to say, remove circlips and clean the bearings/pivots that move when the arm begins to move the trip. I think doing this will get you going at 3 grms. Removing the trip assy will get you tracking less, but the arm bearings are not that free on this late 50's design, also it has no anti-skate bias, so i would not go less than 2.5. But i'd say get it working at 3, with fairly compliant MM cartridges you don't need to worry about wear too much, i play good LPs on mine with no worries. It is one of the best changers and i drop good records on it on auto with confidece. It is better to track well at 3 grms than damage your records tracking badly at 2!
Also, it seems to be normal that these slow down a lot during one part of the cycle at 33rpm. I cleaned and lubed mine fully and got little benefit, i think it is the design. Make sure your idler is grippy enough, and if it gets thru the cycle at 33, i'd say leave it alone. Mine was in a cold climate, but i know it gets hot NY!
If you search the forum, i put a description of my renovation somewhere. The deck gives good solid bass, but they do rumble a litte bit. If it was my only deck, i think i would see no need to buy another, really is surprisingly good!