Advice on 67 Barracuda Convertible

The S was a package that added sway bar etc.. Not all 273 Commando cars were S builds. That car could very well be correct with 10" drums all around and no sway bar, no tach.
Single exhaust is correct for 67 also. Commando exhaust had a resonator tip combo.

There isn't supposed to be a lighter well or anything else to the right of the radio before 68.

Even with its flaws the price is fair. You couldn't build one like it for less.