unfortunately, if it's safety you seek, leave the Model A at home and drive something newer. You may be able to mitigate SOME of the hazards associated with an accident in a Model A but only in a very minor way. While the example you shared is tragic, there is a good chance that they did NOT burn to death but rather were killed by the impact. It's unlikely that a header hard enough to cause the tank to rupture would kill the occupants without the fire. This cars are just a glorified golf cart and things like moving the gas tank and adding seat belts is more feel good window dressing than adding much in the way of safety. I'm not saying that those measures have zero benefit, just that when sharing the road with todays traffic and todays cars/trucks, the occupants stand little chance in an accident regardless of what mods one chooses to make. However, with regards to the saddle tanks previous mentioned, I have them in my 31 pickup hotrod and they fill as fast as any tank BUT, I have the fillers in the floor of the box, not through the splash apron like they are on cars. I also have a '32 style tank on my '28 sedan hot rod and like that a lot. It was mentioned about the "pinto" when the rear tank was suggested but you could make a similar claim regarding the saddle tanks and the square body chevy trucks that had the tanks outside the frame and supposedly would light up in a T-bone situation. The only way to be safe in a model A is to just sit in it in the driveway and DON'T drive it.
