Tonytone,

Read my entries on 5/13 and 6/7 about numbering. I knew Ron and worked in a bike shop that sold his frames in the early 80's. My guess is that you definitely have a late 70's model. Looks like the only difference between your frame and mine is the front derailleur braze-on guide. Mine is under the BB. Your decals are also identical but the name running down the down tube is a bit beefier (and white) on mine.

So if you can find out when that derailleur guide changed you'll find your date.