Hi - not sure if this will help (to you and/or others), but I'm in the home counties just north of London and recently started to look for a good independent Honda specialist for when my 5-year Honda service plan runs out.
The best I've found relatively close by is a company called 'Red-R Performance' in Weedon Bec, Northamptonshire, NN7 4PS (Tel: 07841 164108) (just off J16 of the M1 - 59 miles from J4 of the M1) - they are Honda specialists (web page below).
https://red-r-performance.com/Please note that I haven't used them myself or know anybody who has - I'm just going off their online reviews which are excellent.