Here are some scans of the 4AD parts diagrams., they are quite large and can take a while to download. I left them full size so they can printed full size and not lose print quality.

Serial No. location -- Right side of bulkhead under bonnet.
Engine No. location -- Right side of cylinder block flywheel housing

Engine
Four cylinder, 73 mm. by 89.4 mm. = 1,497 c.c.
                       :in 2.874 X 3.52 cu in. = 91.36Overhead camshaftCompression ratio 7.47:1RAC rated 22 hpMax Torque 77 lb/ft at 2600 r.p.m.Maximum power 58 b.h.p. @ 4,600 r.p.m.Twin Solex 30 F.A.I. downdraft carburatorsIgnition B.12. Lucas coil service No. 45012

Gearbox and TransmissionFour speed gear box with ratios 4.44, 5.58, 8.62 and
        13.25 to 1. Reverse 13.25:1Synchromesh on second, third and fourth gearsHardy-Spicer open propeller shaftSpiral bevel final drive

Wheels and Brakes16 inch bolt on steel disc wheels5.00 X 16 inchGirling hydro-mechanical brakes with 9 in drums

SteeringBurman high efficiency

SuspensionFront independent coil springs and wishbone, rear semi-elliptic leafFront Armstrong telescopic shock absorbersRear Armstrong direct acting hydraulic shock absorbers

Main DimensionsWheelbase 7 ft. 7 ins.Track 3 ft 10 3/4 inOverall length 12 ft 9 inWidth 4 ft 10 inHeight 4 ft 10 1/2 inTurning circle 33 ftGround clearance 6 1/2 inWeight 15 1/2 cwt

Price
Initially for export only