I grew up with pickups and bobtails with a seat tank. I have 6 GMC's with a seat tank and 1 with saddle tanks. I grew up opening gates for a bob tail to deliver gas out in the country. I never give it a thought. I buy repop gas tanks made in Canada because the old ones are so hard to clean. Gas is not as easy to ignite as people think. It takes a spark. And it is the vapor that explodes. 50's pickups were not very safe by design. I remember people getting killed from a front end hit. The steering box mounted to the frame and the steering column becomes a spear and goes right through the driver's chest upon impact. On a hit from the side, the driver is outboard of the frame and there is literally no protection. They are much more prone to rollover and doors fly open during rollover. Seatbelts and headrests were unheard of when they were build. Yet I drive them. But I think the guys who drink beer at Luckenbach ,which is 10 miles from here, and then jump on their Harley with no helmet and no shirt are crazy. As far as saddle tanks, we had a saddle tank get hit in 1968. Tore off the saddle tank and rolled it in the ditch. The other driver was killed in the impact from the steering column going through his chest. Texas has always had a lot of pickups. I never remember a seat tank exploding. but lots of drivers got killed from the impact.