No more bondo than those who put on glass flares. Mine was done by the PO using fiberglass and then a skim coat to fill air bubbles.
That steering wheel was pricey in it's day. It was the Benneton model. Momo made one too.
The only problem with those bumpers is the same problem I had when I bought my car - none of the openings are cut. I hated the look of all of that one color mass on the front end. It was a bitch to mount fog lights and to get the grill opening open and filled. I still dont get the airflow I want for the GT cooler set up.
As far as the rear goes, I recently learned a little something about the 916 bumper - it traps heat. I cut mine open on both sides for the new dual exhaust and my car actually cools off when not under load. I used to work it up in the hills and see 215 degrees. It seemed to take forever to cool back down. Last week it dropped 10 degrees in less than 2-3 minutes. I was shocked.
If it's not rusty, it looks like a neat car. Needs flares.......