I can only offer insight on question number two concerning rust. When looking at a painted vehicle one of the oldest tricks in the books is to use a small refridgerator magnet. Place the magnet on the car and areas with bondo or filler more than just a few mils thick will not support the magnet. Since swedish cars are built with good steel, they stick pretty good. Check in the most obvious places around wheel wells, rockers, doors, and the four corners.

Now if you own the auto and want to locate potential rust, well you start by looking in the cracks and seams. Look on the inside under the carpet and on the inside firewall. Also on the P1800 in each front fender well is a removable panel towards the back. When this panel is removed all kinds of rusty hiding places are open for inspection.

If you are replacing your gas tank due to rust, I would also like to offer some advice. I took my tank to the local radiator repair shop and for $75 they cut it open, dip it for 72 hours, sand blasted, re-sealed it, and then painted the exterior. Point is that it looked like new and I did not have to go through the frustration of find a fuel cell and mounting it. Plus I didn't loose any trunk space.

Good luck. Hope your search turns up NO rust.

Oliver
1966 P1800
Driving old Volvos, not slow Volvos.