If it's like diagram #15 it's available here £3.95
http://www.norbsa02.freeuk.com/goffybulbdiagrams.htm
Not quite, thats single contact, 14 looks promising though

As well as the 2 pin plug,the ones with the punched steel cover,came with fabric covered,twisted 2 core cable.We used to have one in the boot of the Ford E93A,though of course,it was 6 volt.
Yes, mine has the fabric covered cable, no plug though.
The earlier one is a very nice thing with a winding handle for the cable on the bottom. Mine was in a mixed box I bought at a general auction for £3 !!