Ducati 600SS rev counter problem

Hi all, I am new to the site and relatively new to Dukes! Bought my first Duke last year, a '97 600SS which is now due a 12k service. So my first question is does anyone know a reliable non-dealership service garage in the Cardiff area to sort this out?? And my second request is that the rev counter hasn’t worked since I bought the bike; the seller said its probably a cable issue but I read somewhere that there is a common problem where the rev connection goes into the engine block - but can I find the blog where I found this out??? So if anyone can advise an amateur on a simple fix for this problem??? Thanks