I think you'd be safe to say there's around $500 in parts there. The wire wheels could be worth that, but it really depends on their condition. There's a few places out there that will refurb them for you if needed. If there is a serviceable transmission, you've got a couple hundred, maybe a usable gas tank another hundred or so, looks like the bumpers are there, windshield etc. Frame and interior condition is unknown.
You've got a great source for new parts in your neck of the woods. I buy a fair amount from British Parts Northwest. Good people.
http://www.bpnorthwest.com/ There are several other big names out there (Moss Motors, Victoria British) and a good network of "Mom and Pop" places that are selling good used parts as well. Best bet is to find yourself a local Brit car club and pick their brains.
I'm more of a Triumph Spitfire guy myself. (my personal website:
http://www.littlebluespitfire.com/gallery/main.php?g2_itemId=30 ) but I'm not a snob when it comes to British cars - I like 'em all!
Even with the original motor, you can get up and going on the interstates without too much hassle. These little cars are 'quick' and handle like they are on rails. I put an Overdrive transmission in my Spit - I can cruise the highway all day with the original 1500 cc motor. 70MPH at 3 grand on the tach. I did convert it to UK Spec: dual HS4's and a 4-2-1 header, but the motor is still an inline 4 and it's no faster than the factory put out in '75. Probably around 75 horses tops. The biggest concern in driving one of these on the major roads is other drivers not seeing you.
It's very similar to driving a motorcycle, you have to be a defensive driver. Fortunately the horns are pretty loud.
Decent restored value - hard to say as you mention. If it is a well done job, I'd say in the 10k-15k range is a rough ballpark. British cars are like most Coke machines, you generally won't get out of them what you put into them and you should always buy the nicest example you can afford to start a project.
I've probably got $12k (+) in my '75 Spit over the past 10 years. I would jump at an offer of $10k for it, but realistically would be lucky to get $7,500 for it - and it's fully restored. That said - chrome bumper MGB's are a bit more valuable on the market than a square-tail Spitfire.
Good luck - and if you have any other questions, or want to send me some pics, feel free!
Jim