Hello and Welcome to FTE!

the way to authenticate if it's a ranger is from the warranty tag on the drivers door.
the body code for a 66 will read H81 or G81 or something like that, Post all the info off the tag and someone can tell you for sure. Does your truck have bucket seats and a console? that is another way to tell... but, there are fakes out there, so check the body code.

1000 made? i dont know.