The gas smell without the canister is completely avoidable.
At the rear fuel pump hanger remove the line from the vent in the hanger, run a new line down the side of the tank on the passenger side. Under the car zip tie the line off and trim it flush with the side of the tank.
Poof.. no more cabin gas smell.
Now..
for old musty, moldy smells... 99% of the time it is the carpet.
start by removing the seats, clean them and treat the leather, then with the seats removed remove the carpet at clean the shit out of it. old musty smells is very common when people shampoo the supra carpets in the car. The padding gets wet and will never dry if the carpet is left in the car. It will mildew and mold.
I used some carpet anti-mold on mine then let it dry completely before I put it back in the car.
You could also remove the blower and de-dust it, and clean out the air venting. I was shocked at all the dust build up in mine.. It was nasty..