Hi,
My buggy has a single arm steering column 'thing' which does the undicators and also full beam switch/flash. (Wiper switch is dash mounted)
I might be needing a new one so  has anyone got an idea what year it will be from please?
Thanks.

The indicator arm with headlight flasher is 1966-67 as far as I know.

66/67 had a micro switch at the end 67 on is a pull the lever back to dip/main

As Snoopy said the 66-67 is a switch and later is a pull on the stalk.  You can pretty much wire either one in.  I prefer the 66-67 one as the switch is more positive and found that the later ones failed over time.