These are old unused stock that's been sat in a stores for many years, all are in unused,

excellent condition as shown in the photos.

key start with 3 positions.

We believe it is a generic model that fits a number of vintage/classic engines, no specific model numbers 

are shown, no instructions inside the sealed units.

Serial numbers all close to the one shown in the photo, there is a number on the bottom right corner of the faceplate that may match your engine/old unit.

There is a parts list with one of them suggesting the regulator is the 12 volt model - see photos

Price includes UK postage & VAT