Thoughts? 66 Mustang

I wonder why they went to all the trouble to do a cowl and floors and battery apron and not fix the rust in the rear quarters ? For $13 ,000 i would like to see the car assembled completely at least . If the running gear is finished and in good shape that would be a plus ,but i would check out the quarters a bit more because the wheel tubs may be rotted as well and that would not be a cheap replacement .I would check out all the rear sheet metal ,in the trunk and frame rails well first .

Check up around the wheel tub at the fender lip ,65-66 has a problem with rusting the fender lip and wheel tub at the same time ,may be hard to see anything though if it has under coat there .Squeeze behind the lip with your fingers if it is rotted in the wheel wells you may hear it crunch when you do,depends on how bad the rot may be .