thanks for the replies
i don't think that auxilliary lamps are testable (?) so that, hopefully, wouldn't be an issue
i was wondering what lamp units might fit and how to go about rewiring the stalk. i did think about splicing into the h'lamp wiring but think it'd be best to attempt to do it properly at the switch. i'm no autoelectrician (!) and am wondering what might need doing about relays and fuses etc - ? would any of the wiring need beefing up?