Start with the identification plate. It should be on the firewall right in front of the drivers seat, just above the steering column. Post that and we can go from there. Write down all the info as you read it off the plate and post here. If you have pictures in electronic format, go to the club home page and follow the link to post pictures (gallery). Prepare to be swarmed with info!
The first line on the ID plate will start 41-75XX if indeed you have a 1941 series 75. Those first numbers tell you what you have, interpretations available here.
Congratulations on a great find!