The other thing to note with moving coil phono boards is that there have been a few generations. The current boards are Mark 5. I think Mark 2 or 3 boards were around for the longest, and these seem to be the ones you come across most. The circuit is actually the same (give or take a few trivial resistor value changes in a couple of places), but the more recent incarnations have a better layout, and better quality components (the difference between the Mark 2 boards and the Mark 5 boards is clearly audible, and in my opinion can make a very worthwhile upgrade).
It is interesting to note that the phono boards in the modern preamps (92,82 and 52) are again the same circuit, but have been somewhat re-laid out with different connector positions which enable better routing.
The Prefix phono stage is yet again the same phono stage (though the loading is 560 ohm and 470 pF I think), although they have extensively re-laid the circuit out (ie, without the constrictions of having to slot into specific connectors) and the boards are actually put inside a turntable (ie, the Linn LP12 turntable), with the boards being powered from a Hicap, Flatcap or 2 of the Supercap rails. Siting within the turntable has the advantage of allowing the arm cable length to be minimised. Even though the Prefix can be powered via the 52 preamp, I have had reports that it is a lot `better' when given its own Hicap to work from. However, I have also had a report that this is `rubbish' and you are best to power the Prefix via the 52. Take your pick.