Unknown where from. From the video's it's behind a bunch of plastic cladding. This is the model with a long video on cleaning carb etc.
Briggs & Stratton 1022E leaking fuel
Her description is it smells like gas and gets all over them (boots/pants etc) when they use it. It does run as they used it this weekend.
I might give her some B12 and have put a couple ounces in the tank before Friday. I don't know if any fuel in tank currently.
I'm going to say no one ever had it apart. Her father-in-law gave it to them and it sat. She's handy and likes projects but not like digging into OPE or cars. Around house projects no issues. I don't know about him but I know they do bring cars in for service, not DIY.