I found this interesting guitar. There is no information on the label other than model No. states made in Japan. Only S/N 16124 stamped on neck blocking inside the body. Hohner name on headstock is in the same script and position as the old Contessa guitars. Tuners are enclosed gear with knob locks on them.
Numbers on the neck block tend to be additional to the serial numbers, and I can’t find a record of any serialised HG-07 guitars (which doesn’t mean they aren’t serialised, just that nobody has ever mentioned it). They were, as you say, a continuation of a Contessa model and were produced at least up to 1980.
The HG-07 was one of two models, the other being the HG-14, chosen to be a Bicentennial model in 1976. This is a contemporary ad and a recent picture of a full set which was bought complete from Goodwill a couple of years ago.
I presume Phil will be right regarding the number, many Hohner guitars from this period had no serial numbers. According to the list I have from Hohner, the HG 07 guitars were produced from 1978 - 1985, but as the 1976 ad clearly shows, this model was definitely available earlier.
Thank you for taking the time to answer my inquiry. I picked up this guitar for about $50, as well as several others for my small tribe. I had a dozen nephews and nieces arrive from the Philippines last year and I’m starting to try to teach them what I know, including how to play guitar. Now that I’m seeing that this guitar was manufactured in a transition period, perhaps I will keep this one out of the fray.
The locking tuners were a wakeup call for me, I’ve never seen tuners like that. The guitar has some damage to the binding and requires a setup and a few paint rubs on the body which, once polished out should yield an almost pristine specimine. Perhaps I’ll include them in performing that maintenance but I’ll spare this little piece of history from them at least until they show proper respect for the instruments.