The Model Aviation stuff was likely from one of the other Dick Hansen (Hansen) guys who build etc..
The Scale Builder guy lives in Oregon
I am in Utah and the VP is in Arizona -
I do mostly aerobatic and did pattern stuff for years -
I flew scale ONCE got 2nd in 84 at the Nats - (Dalotel -on cover of Dec 84 Model Avaition)
I am too lazy to do really nice scale stuff.
The Cline regulator sets close to the carb and the fuel supply should be tight on all fittings - Jim Cline describes exactly how he thinks this should be done - for a particular engine - contact him directly.
As for fuel valves - I have some nifty slide types a friend made for me - but I still never use any of em -
My fear - borne from seeing the problem -is failure to seal perfectly and allow air to seep into the system when the carb is drawing.
This is seen as a slight bubbly or milky loofk to the fuel whilst the engine is running. It can be intermittant - so I simply use a Weatherhead (tm) solid brass Tee- (75 cents from hardware supplier) and tee from tank clunk pickup to carb.
I put a twig (actually a GP aluminum plug) in the fill tube - that's it -