Based on the distribution of serial numbers in my database, Miki was WSI's prime Japanese source for the upper end models during the late 1970s. These models included the Professional, Semi-Pro,Pro Tour and Super Elite. Basically this covered the models with CrMo tubesets, with the excpetion of the Elite (I don't have any Elite from this period in the database, so I can't say if they were Miki builtor not). However, Miki also appear to have been alternate source for the hi-tensile models in an emergency situation, as there is the odd LeMans with a Miki serial number.

Circa 1979, WSI started transferring manufacture of the high end models to a new source, though Miki still had significant volume in 1980. However, after that they still appear to have used in emergencies, as the odd mid-1980s Turbo has surfaced with a Miki serial number.

In terms of frame, the Miki built Centurion Professional is a clone of the Acer-Mex built Centurion Professional and Windsor Profesional, which itself is a Cinelli copy. The head frame builder at Acer-Mex was Remo Vecchi, an ex-Cinelli employee who simply replicated what he had been doing in Italy for over two decades. This is why the Windsor Profesional looks so much like a Cinelli. When Mitch Weiner was looking for a high end model for his Centurion brand, he approached Acer-Mex, who built the very early Centurion Pros based on the Windsor model. When production was transferred to Miki in Japan, they simply continued the established frame aesthetics but used Japanese sources for the tubing, dropouts and lugset.

Regarding Pro versus Semi-Pro, the main distinction is the seat stay attachment to the seat lug. The Pro used the Cinelli style fastback arrangement, while the Semi-Pro used a British wrap-over style. Component specs could vary from year but they were typically quite similar with the major difference being tubular wheels on the Professional and wired-on wheelsets on the Semi-Pro.