Thank you for your post. I uploaded a couple more pic to my Dropbox. You can view them at each of the links below. Please let me know what you can determine from these markings. Based on the links Mike sent, it has several markings with many different years.

Here are the links to the pictures:

https://www.dropbox.com/s/t1pcornrtyymj92/image_67178241.JPG?dl=0

https://www.dropbox.com/s/6lek2dzf69cvy3w/image_67164417.JPG?dl=0

https://www.dropbox.com/s/6xryu3imkwu9y33/image_67186945.JPG?dl=0

Thanks,
Joe