The 1393 amp was a very short-lived amp in the 139X line, and was only available in the Fall/Winter 1957 catalog. 15 watts into a 12 inch speaker, with two control tremolo, three tone, footswitch, and four inputs. Frequency response rated at 60-15000Hz. I reckon Sears thought that it split the field a little too much, so you jumped from 10 watts/12" speaker (1392) to 15 watts/15" speaker (1394) after the 1393 was retired. Obviously, a rare amp.

Introduced/Retired:
Fall/Winter 1957 at $92.50
as the 57D01393L