I was talking to the nice man at Rona Sewing machines in Waltham Cross today (18/02/19) and he said that he has at least one (I didn't ask how many or how much) of the Juki 735 combined coverstitch and overlockers. These are usually only available in the States. This might be of interest to someone.
It is a great shop, as well, if you haven't used them - very reliable and helpful.
https://www.onlinesewingmachines.co.uk