hirscwi: Apparently he's got an AT140ML with ATN140ML installed in the AT-ML170/OCC box, an AT15Sa or -SS body with an ATN15SS installed in the AT140ML box, an AT15Sa body with ATN15 installed in the AT15Sa box plus an ATN15SS in the matching box within a nice box of some higher end AT model (not sure which one, though).
So the AT-ML170/OCC plus needle are missing, but instead he's got a second AT15Sa/SS body with ATN15SS - which may seem a tad less great at the first glance, but in practice might just as well be preferable, as replacement needles for the AT-ML1x0(/OCC) family by now are unobtanium anyway. Might be a good idea for 63V to grab one or two of the ATN15E needles, though, provided LPGear still offers these for a fair price...
majick: I don't see that much of a problem in terms of arm compatibility - however, you're definitely right that a PS-LX350 wouldn't yet seem a really adequate platform for these cartridges. However, a nice used Thorens, Dual, Luxman or whatever with more suitable quality and more ideal arm wouldn't be that expensive.
But as the whole lot now turned out to be rather not new and unopened, of course 63V now has foremost got the problem, that he has yet to find out what condition the stuff actually is in...
Greetings from Munich!
Manfred / lini