Looks good from the outside.
But you mention something that raises my interest....Fiberglass fenders are a bit strange, as the front fenders are a originally welded on, as they are part of the structural integrity of the car. If one would just cut out the fenders and replace them with fibregass, how would the rigidity of the front end be maintained?
It seems like all the bits are present and make it a nice drivers. I mean interior etc. Biggest question to me would be the rust monster.
Did you have a look up into the area behind the glove box, atop where the vertical part of the firewall meets the side of the A-pillar ? That is a tell tale spot for corrosion.
Other spots are the rockers / sills. Your car seems to have the screw- on rocker mouldings (also called decorative trim) on the sides. They are a metal plate running front to back, with a clipped on chrome+rubber trim. The entire metal plate can be unbolted; it offers a view of the outer (first) of the 3 layers that make the sill. The intermediate (2nd) layer is hidden inside the sill and can only be seen with a optic fibre camera through some inspection holes on the inside. The 3rd layer of the sill is the interior side, can be viewed when lifting the carpets.
When looking from under the car, with the rocker moulding removed, you can see the spotwelded seam of the outer (1st) and inner (3rd) layer together.
Last point are the 4, round, drain holes.
If those locations look solid, you have one less worry.