Brady 30, FYI, the Miyata 414 was 10th in a line of 12 road bicycles. The original MSRP was $380 US. The original Blaze components were SunTour's 2nd from the bottom of the line road group at the time. The 414 would be considered a sports bicycle, on the cusp of entry level and mid-range. It was geared like an entry level recreational/touring model but had slightly more aggressive geometry, though not as aggressive as a racing model. It was targeted at club riders and novice triathletes. You can find all the specs in the 1990 Miyata catalogue here:
Miyata Bicycle Catalogs: Miyata Catalog 1990 (100 Year Special Edition)
I'd appreciate it if you double check on the serial number. My database has several other Miyata STB models from 1990 and they all follow the standard format. TIA.