Aw..... he looks like my Mr. Sissy Cat!
I understand about the foul smell. My two ferals were STINKY inside and out when I first got them. It took probably 2 weeks of good, nutritious kitten food and clean water (and baths) before they smelled neutral. Their litter box was unbelievable. I think it must have had something to do with what they were eating. Bugs, dead animals/birds, whatever their mama could find for them. Her milk was probably affected the same way too.
Luckily, it does get better! My two kitties are the sweetest smelling kitties these days. Hang in there!