As the latest bodging seems to be successful this is now for sale.
The Pre3 is a 5 input line stage using two halves of an ECC82 per side and an output transformer with a fairly large ratio to get down to something like a reasonable gain. This particular one has been wired for balanced outputs via mini XLRs which gives a gain of x12 or phonos, but not both at the same time. It can also be wired for x6 gain.
Just to be clear, this will need an offboard power supply putting out around 20mA at 250V and a bit less than an amp of 6.3V heater current. The World Designs PSU3 is the original partner but those of you with DIY skillz should be able to make something fairly easily.
There has only been slight attacks of foo, with a Ko-on pot and CMC phonos for the output put in. Current valves are some 6189s which have had a bit of use.
250 quid to anyone? There is no such thing as original packaging and the trafos add a bit of weight so it would probably need to be collection or taxi.