Lucas Headlight Lamps
Lucas manufactured several styles of headlight. These include the popular PL700 and 700, as well as Le Mans, Cats Eye, Fog Ranger, and a whole line of motorcycle lamps. Recent copies of many of these are in wide circulation. This chart is intended to help in identifying the correct bulb.

 
Model: 415(LHD), 
414 (RHD)
Base: P36d(US), P22d(Europe)
Style: T9
Wattage: 50/40
Incandescent
(Available in Halogen)
Model: 410
Base: P45t
Style: G12-1/2
Wattage: 45/40
Incandescent
(Available in Halogen)
Model: H4
Base: P43t
Style: T4-5/8
Wattage: 60/55 (typical)
Halogen