Norman,
I'm embarrassed to admit that I don't remember the exact valve we used when we did this, but if you have one of those fast disappearing type of auto parts stores where they haven't yet installed the parts selling robots behind the counter, they may show you their manufacturer's application catalogs. These are cool, and are full not just of all kinds of parts you may be able to use for conversion work, but they have clear drawings and complete specifications. That's where we look for heater blower motors that were meant for winter!
The valve we used had, I believe, a ball valve with a cble operated lever. The outer jacket of the cable fastened right into a bracket which was afixed to the valve. I may have had to drill a new hole in the lever to get the ratio to match the dashboard control's, but it was little trouble.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon