@ Hiten, I inspected the original idler wheel closer and was quite surprised to realise that it uses a two part bronze bushing, possibly sintered. I did some browsing and found that igus polymer bushings (model name iglidur) are available in the required size of 2.5 mm internal diameter (and OD of 6 mm and 3 mm length). I learned something very interesting from my machinist recently - he told me use two bushes, one at each end of the coupling, if you want to reduce vibrations. And that's exactly what is used in most platter bearings, and even on the Lenco idler wheel!!! I think it is a track worth pursuing (igus bushing instead of the traditional sintered bronze bushing, together with the idea of machining the wheel from a single piece of brass). Machining from a single piece takes away one source of variability - perpendicularity of the bushing assembly with respect to the wheel plate. Most machinist can do a fine job with turning, and will produce something that is true. But where error creeps in is when trying to pressure fit the bushing assembly to the wheel.I guess it takes a more sophisticated tool than a hammer to fit it exactly right.
To extend this line of thinking, one can also try igus bushing for the platter bearing. But reading from the experiences of people who've done this, it seems the spindle is a loose fit, so if one wants to go the whole hog, one should make a fresh spindle as well. I'm not pursuing this for now as I don't use the stock bearing.
Will try 47 kohms soon. But the product leaflet for the DL 160 says >47 kohms loading, which was the reason I tried 68k. 
