I am not sure about any one-way valve, but Corky said the restrictor is not necessary. Where exactly does it say the oneway valve goes. If you need any parts for the Regulator, I will buy them for you from Bell. Let me know. The regulator was removed straight from my car and set into a box, but the small hose with the restrictor got misplaced.
The one way valve goes into the linel to the petcock or adjustable valve (5/32) fitting. They don't look expensive, but it says they're necc. Bell is closed until Monday. BTW check my post about intercooler piping.