Pretty sure that the one that wasn't labelled "Made in USA" was made in the USA, earlier than the others.
I believe the first two characters in that serial number stand for:
9 - 1989. In the 90s Faball started using two digits for the year
U - Utah manufacturing plant
You're close on that.
9 would be the year. In this case, 1989. so in this case:
1. 9UA09148 = 1989, Utah (Salt Lake City) plant.
2. 93UA18739 / MADE IN USA = 1993, Utah (Salt Lake City) plant.
3. 5B049200 / MADE IN USA / KBC = 1985, Baltimore plant.
BL.