On older engines , the numbers will be stamped into the shroud. They may be covered with paint or rust, but they will be there. Here is link showing where they should be. Usually near the spark plug hole, just above it. If that is no help I will also include site showing the Briggs carburetor, may be you can pick out your type.http://www.jackssmallengines.com/briggs_and_stratton_model_locator.cfm http://outdoorpowerinfo.com/repairs/briggs_stratton_carburetor_cleaning_repair.asp
Thanks for that , it is the carb below.
Here is a listing for similar setup, from Sears. It has the same carburetor. They show individual parts and gaskets, carburetor listed in no longer available. Will this help?http://www.searspartsdirect.com/partsdirect/part-model/briggs-stratton-parts/all-products-parts/Model-171700TO17170600100016/1245/1503500/00025676/00002?blt=06&prst=&shdMod=
Yes that helps , by the way I found the serial number on the shroud where you said it would be, I ground off all the rust and crud and it was there stamped into the metal.
191707 601901 89120510
Ok, here is linkto parts list.http://www.partstree.com/parts/?lc=briggs_and_stratton&mn=191707-6019-01&dn=9634004AC