Hi Jan, --- Thank you so much for digging up the additional references. It's interesting that it differs somewhat from the existing ones I have insofar as word length and power consumption. The new figure of 200-Watts seems more plausible than the 100W the other sources give. The new reference also reveals that production didn't start until 1963. With no mention of the previous UM-1 model, one can only assume that it wasn't produced in quantity. --- Truly useful parts of the puzzle. Thanks, Steve L.