I said...."My only concern is that I may have bought an oak tree when an acorn would have done!"
Today I managed to get 'The oak tree' onto a bench..Levelled it, removed rollers, filled with water..no leaks and turned it on. Pumps sprang into life and the 8 degree C water :o started to heat up. I didn't realise at first that the drive spindles were rotating until I wound the speed up but they were.
So so far all seems to be ok.....I then ran out of time to test it any further so haven't measured the final temperature against my digital thermometer yet.
The rollers are in good condition and can be manually rotated so it looks as though I may have a 'worker'