The S2 shell (either with SME's black gunk or a piece of green card-table baize which works well for pennies) will take the Stantons, Pickerings and Nagaoka's, although the Sumiko shell may stand you in good stead for the future
The SME internal wiring can be fairly easily replaced I gather and SME themselves have a comprehensive list of parts on their website. If you want to have a go yourself, the Terminator arm chap on ebay sells some fine wire which would be a great alternative (the cardas stuff is a bit thick I understand) and I have some ready myself.
As you know, the vertical bearings are knife edge types and as long as the Nylon isn't damaged, they should be fine. An F200 damper with baby-oil or similar is great for stabilising them (the standard SME fluid is too heavy, even with the reducing fluid IMO). The horizontal bearings can be adjusted but not as finely as the "un-improved" arm I found for some reason. The weight of the arm-tube, counterweights etc should load the horizontal races anyway and prevent them "chattering."
I can't go on and I can't go back, I don't feel so matter of fact,
I tried and tried to make good sense, What's the good to try it all again?