Many thanks for detailed reply - very pleased to see you have already been working on those reflectors and they look useful.
I have to admit I've put my 122 GHz Tx/Rx on the shelf waiting for a suitable antenna system - suitable = something easy enough for me to cope with. Looks like the arrangements you are working on could be the answer. Please could you put me down for one of these once you've finalised the design? I'm quite happy to wait at the back of the queue, as I'll be waiting until Finningley is open before starting. Hopefully, by then Kev will have his sytem running so tests across the fields will be possible.
Did you ever have any success with the SSPA boards one for 13cm that you were looking at, It was back in 2019 Martlesham.