I still have two of the new old stock cr-moly Koga-Miyata framesets, 58cm. Still in their original packing. They were built in Japan in the mid 1980s. Label says triple butted, hand built.
126mm rear axle spacing, 40 inch wheel base. The wheelbase is long enough that these would make excellent commuting, or sport riding frames or fixed gear also. They don't have eyelets on the dropouts, but you can use rubber backed clamps if you need to put a rack on. Let me know if you are interested and we can arrange for you to see one.
The sizing sound about right. You mentioned 34 inch inseam. I wear 32 length pants and these fit me about right. It sort of depends on what type of riding position you are looking for.
They come with headset and BB installed. I also have new 27.0 seat posts for them, which is included. $290 for each frame. This is considerably less than a Chinese frame would cost today.