I also have a PCQ-PF model. I think the side mount version (which came out right after I bought the PF model) will work with more machines than any of the others since it just attaches & detaches from existing carriage. The sales person at PC Quilter will be able to tell you precisely what you would have to do to your Lenni and/or Bliss frame to make it compatible if it is possible. I know they have users in the UK but I am not familiar with your frame at all. I have a ProFlex frame with a Voyager machine.