The Hondo II brand name was introduced in 1974. I've got a 1975 Hondo catalog in the acoustic guitar section and all models are designated by an H and 2-3 numbers so your guitar isn't one of the very early models. This is a good thing since it took a few years to get the quality of the instruments up to snuff.
Based on your research, I think you are safe in concluding you have a late 70's model. The fact that your guitar is stamped Made in Korea and from the late 70's indicates it was most likely made by Samick. Take a peek inside the soundhole and see if your Hondo has scalloped bracing. This type of construction would be consistent with late 1970's Samick techniques. Here is an example of what I mean:
 
Just as a bit of trivia, in 1979 over 790,000 Hondo instruments were sold worldwide. They were busy.

