hmmm .. nice ones --
a bit more serching has brought me to
www.servocity.com which has
Worm Drive Gearbox (Vertical Shaft) Product # WDG30P
used with a
1 RPM Gear Motor Product # RZ12-3000-1RPM
gets me down to 30min/Rev which is roughly where i want to be ...
(they also have a 0.5 rpm .. 1hour /rev .... might be too long ...
not inexpencive & i'm worried about vibration but may have to try it ....