The WGA carbs were designed to run in a completely closed environment in a chainsaw...Chainsaw carbs have air filters and are otherwise closed off to any influence from outside air...I haven't tried it, but is seems to me that a scoop facing the rear with some air filter material in the opening, and otherwise tight on the carb, would do the trick..
Restricted opening making it run rich ? That's what the needles are for.
An airfilter along with a fitting on the cover with tubing through the firewall will duplicate the original setup of the carb, no outside air will influence the carb settings...
Surprised no one ever thought of this, there are millions of chainsaws in the world set up exactly this way...Ever hear of a chainsaw cutting out when turned at any angle ?? No way