To do it seems simple, its just a barrel to which we fit our original parts into with a machined bayonet fitting to mate with the AGA front plate. I could do drawings for the basic unit.
Will require some thought as to fitting the OC bail. The OC part can be fitting an 'ABS Octopus' or other onto the DSV.
Would be as neat as Bob's ADV.
The best way to do this cheaply is to make a square block with a new shut off valve for the ADV, a bit like a three way valve on your central heating.
look at
http://www.divenet.com/divematics/mouthpiece/ and you will see what I mean.
I could probably do drawings for that too.
The OC will stil need an inline shut off valve so it doesn't act as an ADV. The down side is you will have to shut the DSV then open the pneumatic valve. I can live with that to save that much money.
Thoughts would be needed on;
How to retain the rotary valve in the housing. Divematics use front retaining, I think this makes it larger than it needs to be. Any good ideas?
How to seal the valve vanes. Needs to be reliable and simple, I like the Draeger way but it makes it stiff.
How to 'cheaply' manifold the OC to the DSV, maybe an adaptor block that is bolted on the underside of the DSV but if you dont want it, you can use a blanking plate?
Maybe we should sort out a good design then ask John to get a price.
Hopefully we can find others to join in as a syndicate and keep the cost down.
Chance would be a fine thing, but yes please. If you know, please share.