Thanks for bringing us up to date on the project. In case it is useful, here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6ntzHVJ1DajI.pdf
and here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/mssAIQ-K_ny7tH217FzoPu.pdf

I believe the Flo-Jet carburetors used on the gravity feed fuel systems are better suited to easy starting and rapid throttle response than the suction carburetors used on the small engines, but you have the hassle of turning off the fuel or suffering the consequences, which sometimes include a sump full of petrol.

I'll close this thread - if anyone needs to post to it, please PM a moderator.