Bloke in Bristol needs help

Hello . a while ago I sold a boxford tcl converted to mach 3 to a bloke in Bristol who does custom car builds . He picked it up and I demonstrated it working and he took it away. After a few days he complains it wont do all sorts of things So he brought it back 180 miles 1 way and I reset some setting's and a presto it works fine. So he took it back home and very strangely it wont work. Is there any body in Bristol could go have a look for a payment from him .If any one interested I will give contact details .Thanks