Hi, and welcome!
Check the "Technical Data" section at the top of the page, and look over the "Series Alpine..." article. It'll fill you in on what you've got. The VIN plate is under the hood, on the right side of the car. While you're under there, check the engine serial number. It's stamped into the block, on a flat facing up on the right side, also. Just forward of the oil filter on many cars... just rear of the fan belt and hoses about halfway down the side of the engine. If this number matches your car's VIN, then you have the original engine. On many cars, though, the engine has been replaced for a variety of possible reasons.
The VIN has some information about factory options, but after forty-plus years, they may have been removed or replaced with something else, too. Keep this in mind before you buy a bunch of parts. Lots of info here in the forum, and lots more available from the home page of the site. Click on the "Invasion" link, too, to find out about the world famous Sunbeam Invasion get-togethers on Labor Day weekend.
Good luck, and happy motoring!
Ken in Columbus