getting rid of the engine/trans and related components will throw you over 1k# to begin with.
If it were me, I'd get rid of the ABS system too, and probably the power brake booster. You can adapt the brake system to make the pedal easier to push, by either changing components, or changing pedal leverage.
I'd be interested in finding a lighter driveshaft, or eliminating it altogether.
The hood is ridiculously heavy, and is relatively easy to clone in fiberglass. If you can lay fiberglass, you can cut the fenders down to frames w/ the stock bolt locations intact, and lay FG in.
Door skins.
Deck lid.
You can feasibly hit 1500 lbs total weight by lightening that car. You should more likely shoot for 22-2300 though, and if you're comfortable going further than that, it's all "downhill from there" so to speak.
Aeromodding the ThunderChicken is relatively easy, too, since it has a nice, long, coupe shape to start off with.
Probably the single best improvement you could make is to extend the rear roofline of the car down to the trailing edge of the decklid, essentially making it a hatchback. That alone would give you the same relative shape as a Corvette!
The heaviest components will be the suspension and braking systems, since they needed to be larger to deal with the extra weight of the car itself. Find alternatives for those, and you're golden as far as weight loss goes. (Don't mess with the brakes too much if you're not familiar with them - weight isn't as important as stopping)