One like this should fit.
http://www.scooterrestorations.com/lamb ... lb-holder/I don't know if there are 2 types of GP bulb holder but would guess so, probably more.
There are 2 types of Vega headlight however, only 1 of which I understand is compatable with a GP bulb holder.
Mine is although it didn't appear so at 1st. I think I have the CEV headlight but will check later & report back.