Any issues with a "mint" PS Audio 4.6 pre?

I've just bought one of these at auction (it is yet to get from the US to Astralia. What are the likely issues I may need to deal with regarding this unit? It has been bought as a phono stage. Is it likely to be better than my Cambridge Azur 640P dedicated phono preamp?
I have a PS Audio II phono preamp which has been in my system for several decades. I think that the later PS Audio preamps were all built around the original basic phono circuit, which I don't think has been improved upon. This original circuit was exceptional in its time in that it used a passive RIAA equalizer and still achieved very low noise. In later models they boosted the gain so that it could handle MC cartridges, and IMHO, performance was degraded. The switching, volume control and line level gain of the "full" preamplifier units is conventional.
I have the 5.6, which I presume has some similarities with the 4.6. Nice build and good quality components throughout, so if the 4.6 has been properly used there's nothing to worry about. I partly agree with Eldartford: phonostage is good, and IMHO the MC part isn't half bad. Although the phonostage in my Aragon pre is better since you can adjust the load. I'd guess it'll be an obvious improvement on your Cambridge.
Definitely a step up for you especially for use as a phono stage!! You will love it...totally new soundstage!

The only thing I had to recently do with my 5.5 (which is older than the 4.6 I believe) was have the volume control and selection knobs 'cleaned' they was some static when you adjusted them, but that is to be expected with something over 20 years big deal to me.

I am not 100% sure, but most PS preamps from that time have the external power supply. This is crucial that the power cord be in good condition. Did you check to make sure the 4.6 comes with it, and if so in what condition??

hope this helps, older PS equipment is interestingly enough better than most of the new stuff to come out!