Now I have the verdict on the clutch pack. I received it today expecting to see a different pressure plate and different clutch center. I was right on one of those counts.
The clutch center has (as I expected) the ME2 marking on it and it is quite different but the pressure plate was stamped 390 though just like the one I have. The springs were also different on the pack I got off ebay.
There were also four washers under the springs on the one I got today. Upon closer inspection, they were definitely hand adapted. The springs from my old pack are actually far closer to the service numbers I see in my manual. It looks like someone added some longer clutch springs then put washers under them for even more lift. What were they doing, drag racing?
The "new" pressure plate also has gouges from what looks like the springs so I'll use the one I have. I'll need to painstakingly file down the grooves on the center (again) but I should have all the proper parts in order now.