Surrey is a big place so a couple of places like mentioned Phirm has a good rep, but not sure if they do the old stuff anymore TBF without an ECU socket its a dying breed

Depends
what you need doing as long there garage is full of classic cars being restored or fixed is a sure sign of a good workmanship.
Living in Surrey is a double edge sword
(1) They all think you own a money tree

(2) There is a Surrey TAX on all tradesman which is about 25% above market value

(3) Gave up looking for a decent garage in 1990 and fixed things myself.
I'm guessing you need a mobile mechanic to come to you depending where you are located?
I do know a man who can work on gearboxes and engines all day long if you want PM and I'll pass his number onto you.
Expect about £40 or more per hour though depending what needs doing?
Phirm Address: Unit 2 Winkworth Business Park,
London Road, Hartley Wintney,
Hook, Hampshire RG27 8WP
Phone:0845 450 5760
VAS MOTION01483 577782
Unit D, Perram Works
Merrow Industrial Estate
Guildford, Surrey, GU4 7BN
For parts I use
Driftbridge (ask for Martin at parts desk he knows one or two mechanics

)
Address: Reigate Rd,
Epsom,
Surrey KT17 3LA
Phone:01737 360111