One French Solex 40mm updraught caburetor, type 40 VAFD N
The mounting holes for the intake are 50mm apart. The mounting holes at the top (where the screws are) are 45mm apart.
Rolls Royce strong/weak carburation adjuster for on steering wheel. For 40/50HP Rolls Royce. Numbers on back of casting difficult to read, I believe it says 7 71AT1. Teeth in good condition.