I picked it up last night for $300, which is about what the parts to upgrade my 4530 would have been. It's actually a custom industrial setup based on a 4400 and it took me a little while to figure out what I had. In addition to the stock lathe, it came with a 6520 dove tail headstock (that was apparently used as a tailstock) and a riser plate and pivot pin to raise the factory headstock to the same height. Both headstocks have spindles with a 9/16" ID and no Morse taper (Sherline p/n 40239). This should allow me to pass through stock as large as 14mm, which is a big plus. It also came with 2, 3-jaw chucks.
In order to use the tooling I have, I'm going to lower the headstock to the original height and use the standard tailstock. I can always change the configuration if I need to for a special project.
The cross feed table had been modified, so I'm going to replace it. I need a few small parts, but I'm going to end up with a second lathe with much improved capacity for relatively cheap money.