Did you check areas other than the BB shell?
TBH, I didn't. I didn't expect serial number anywhere else, that's why. But I will give it a another try and carefully check other areas.
squirtdad thanks a lot.
Some Miyata frames are very narrow and fussy about tire size. Be sure you tire/rim selection will fit.
I will definitly take that in mind.
I have little update regarding to tires.
I found good condition tires at local bike track, got the glue and I'm gonna install them when I get spare time. Since, my tires was completely useless, this will be temporary fix for them. For the future I'm going to convert wheels to clincher. That will give wider choice of tire, easier fix for flat tire etc...