Engine stalls upon braking

I'm thinking that carb has the vacuum port under the throttle plates and pulls a high vacuum to the advance canister when the throttle closes. Dwell changes wirh vacuum advance, and if the points aren't opening, engine dies, more likely when engine is warm. There is also a very particular weird sickly sweet smell when starting a hot engine where the points aren't opening.
I was once at a Circle K in Phoenix in a stupid new rental car, and a beautiful red '64 Galaxie XL was parked next to me.
They came out, it wouldn't start, and I thought, Ooo-ooo that smell, can'cha smell that smell?
I opened up their points a little and they drove off happy.