Klyne Preamps

I've just bought a Klyne 6LX3 preamp online, which I have not yet received. I probably didn't do as much research as I should have before buying it, and this model doesn't appear on the Klyne website.

The current models appear to be the 6LE and 7LX. Is the 6LX an earlier version of the 7LX, or one of the current 6 series?

If it is one of the "lesser" System 6 preamps, how do System 6 preamps compare with System 7 preamps?