The very first Hondas to arrive in the US in 1959 had turn signals included, but shortly after the DOT ruled that they were unacceptable on motorcycles. This restriction was because they were thought to be too small and close together so-as to be confusing to other motorists when used. (After all, turn signals were quite new even on automobiles at that time.) It wasn't until the late 1960's that this DOT restriction was lifted.
With the restriction on turn signals in affect, the US models were available from Honda in the American market only, with a designation containing "A" (e.g. CA77). Elsewhere (e.g. here in Canada, eh) those same models were provided with turn signals and the model designation didn't have the "A" (e.g. C77). This distinction applied to other models as well - the C92, C95, C100 all came with turn signals whereas in the US they were known as CA92, CA95, and CA100 and there they didn't have signals. The CB72/77 was a special sports model that rarely came with signals; however, some did and had higher bars as well when they were mounted. (I believe those CB72/77's were known as CBM72/77's and were mainly available in Japan early on.) the CB125/160 (very similar in styling to the CB72/77 never came with turn signals, as far as I know.
Those "nameplates" posted at the start of this thread, look very much like what I would imagine (never having seen an American version) were the plates that went on the rear shock/fender plates where the turn signals were mounted on non-American CA77 and CA95 models. On the C100 model, the rear signals mounted directly onto a hole in the rear fender, which on the CA100 version was plugged with a plain painted cover, instead of a more fancy aluminum casting with the Honda name on it.
