Whoever told you it was from the 70s is waaaaay off. That style is called a Becket Zip and wasn't even introduced until 1993. Yours looks genuine.
ANY Coach that has at least one letter of the alphabet in its serial number, assuming it's genuine, would have to have been made no earlier than 1994, which is the year code in your bag. Before 1994, serial numbers were numbers only, no letters.
BTW, just for future reference, the forum Rules don't allow linking to your own auctions since some unscrupulous sellers have done that in order to advertise their own items. Just a heads-up in case your post gets removed. You can post your own photos but can't post URLs of your listings.
The following set of six Salearea Coach Guides posted at Ebay have a lot of accurate information on Coach, especially older styles made before the move to China:
http://search.reviews.ebay.com/members/salearea?uaid=41262657&uan=salearea&uqt=g