My opinion
Before you offer him money you need to know a few things. You might get dirty and you will have to de-snake the car. Ask him if you can pull it out of the garage to inspect it. You can always push it back in and go home.
1. Does the ser # on the rt front block pad match the car?
2. Has the body been busted and patched or is it solid and straight?
3. Are all of the hard parts there, other than the intake, carb and trans?
4. What are the options? (p/s, p/b, A/C, hardtop ect.)
5. Has the car been modified in body or mechanically?
I can't imagine why anyone would swipe an iron intake so there is a real possibility that this car is a 327/350hp which, by the way, was the most popular engine in '67. The intake, carb and trans aren't that hard to come by. Any restoration of a mid year is going to require a complete interior replacement/restoration so that becomes a non-issue except for bargaining purposes. Options become a plus. Being a FL car, it might have A/C. Very hot with restorers.
Bottom line. If it is solid/straight, correct engine, optioned, and fairly complete other than the aforementioned items I would say you have an excellent restoration project car there. Offer low and work up. With the condition of this car I think it would be impossible to insult this guy. Don't worry about it.
What to do with this car? Well, it isn't what you want so the answer is nothing. Clean it thoroughly so the NCRS guys that will come to look at it can see all the things they need to see and that's it. Take the money and look for that chrome bumper Shark.
As to true value, '67 is one of , if not the most popular year with restorers/collectors. Especially optioned cars. If it is mostly complete. correct engine, straight and solid you should be able to get 5 figures for it as a project car. Keep in mind that $50,000. for a frame off NCRS quality restoration is not uncommon.
Check the ads. You won't find a cheap '67 in any condition, except totally destroyed. If anybody finds an ad for a '67 project car that is a good straight start for much under $8-10,000 I would like to see it posted on this forum.
Just my opinion.
Tom