"So, what's the REAL skinny? How many styles for the SD-1 did Ketron release in the, what, four or five years it was on the catalog, which had ENTIRELY new styles (not translations from earlier MIDI styles) and which had entirely new audio loops for the drums?"

It's pretty common for manufacturers to carry over styles from the previous keyboard. I don't see this revelation as a "ah ha" or "gotcha on that one" moment.

How many styles were born on the E86 that were carried over to other keyboards ? Same with Korg. I-3 styles were carried over to the I-30 etc...