Hi Alistair,
I had my bespoke one fitted by Watling in Hertfordshire… https://tinyurl.com/y8km4tdy
I wanted a particular feature (a removable drawbar) and the socket to be mounted out of sight, which means that the towbar is almost invisible. Mine is to tow my motorcycle too. Watling did a wonderful, very professional job, completed the same day while we wandered round Watford.
This is the second bespoke towbar I’ve had made by them and I’ve been delighted both times, so I feel I can highly recommend them.
Barry