I purchased a used 1976 HLV and love it. It came from and IBM lab out in Denver.
I have the collets and use those most of the time.
I also have the 3 and 4 jaw chucks - these are very common on ebay
I'd like to have the 6-jaw chuck, but these are not so common and are expensive.
Parts are available for the HLV models from Hardinge and they are expensive.
Just pretend you're buying and restoring a classic Porsche and you'll be prepared for the prices!
I would not recommend purchasing the older HLV-BK style as parts are pretty rare for these.
I had one years ago and sold it...
If you can get a Hardinge HLV toolroom lathe in good condition, there's not comparrison to an Asian import.
You will love it - especially threading.
My HLV is a tad worn out and I can hold 0.0003" taper over 3".
Good luck with your decision!