i only manufacture. my neighbor recently bought at an auction.
prices around £600 seem usual.
you need the hvy walterscheid pto
look at the main bearing housing - it should have a round exit hole for the tube.
very old m/c's had U shaped frames and 1 3/8 splines.
you need the 1 3/4" splines for today's power.
impellers changed for the better about 8 years ago, and fully interchangeable with all stirrers
the making date is on the top of the top link plates