To correct some information from earlier... Univega did not rebrand Miyata-built frames. Miyata built them under contract. Univega designed bikes and had them built by others (first in Italy: Italvega) and then in Japan. Miyata then built similar models based on the Univega designs (there must have been some agreement between the two companies). Some are exact crossovers (e.g. Univega Specialissima = Miyata 1000) others are just similar. They were great riding, great looking bikes with nice, high quality, tough paint and very good geometry.
Cheers,
Karl