I talked with Jim Cline today and he says he started making the Cline regulator in 1990.

That it originally used the regulator parts from a Walbro WT-158. That carb is now obsolete.

But the Walbro repair kit D10-WAT has the diaphragms and gaskets to fit all the WA and WT series Walbros. Bought two of these kits at the local lawn mower shop, one for my Echo leaf blower. He says that the gasket you use with the diaphragm should be .030" thick. If not, you may have to adjust the lever. The Cline from the factory is set up to require a 3" WC vacuum relative to existing atmospheric pressure on the outlet before it will open.

He says you should keep the diaphragm sealed up at all times to prevent it from drying out and cracking. Someone in another thread mentioned putting a loop of fuel line between the inlet and outlet.