Can anyone post diagrams of the different types of keyed stop valves? I’ve seen diagrams somewhere in the past 12 months but a search has failed to find them.
BTW there’s a nice Rogge wooden chanter-top with stop-key for sale on uilleannobsession at the moment.
They are on Chris Bayley’s website but his site seems to be having some problems as the links are hard to find. They can be found on the A-Z search page under Union Pipes - Stop Keys
The one on my Bayley set is slightly different to those shown and uses a quadrant shaped section of brass operated by the key which in turn pushes up a bent rod to keep the valve leather open. Works very well and does not impede the flow of air.
Thanks. Exactly what I was looking for.
GHAWDD, I love it when a plan is initiated and resolved this quickly! … ooooops, wet’em. 
IMMENSELY COOL!!! Thanks 