So, Century Optics does NOT make a 37mm 2x telephoto adaptor, correct?

I can't answer that, but there are a couple other threads here on telephotos with 37mm mounts. I'm really happy with the Sony High Grade 2x, but it ain't cheap. With that lens, plus full zoom, plus 2x digital zoom, sunspots are clearly visible on the setting sun as are craters on the moon. Very nice.

Staring into the sun, Boyd! Tsk tsk. You're mother taught you better, surely! ;-)
Yes, the Sony high grade. My other choice.