The natural-finish XB-400 is still my workhorse bass. I love the ones in transparent colors BUT a ding just totally shatters it -- the XB-500 I bought used (in teal) is missing about two square inches on the bottom bout where it was dropped, & ALL the finish came off, right down to bare wood.
The Bantams were made like 1994-2005. The 400 was made only 1994-1999 -- given that, yours is likely 1997, & at a guess rather late in the year.
I'm pretty certain they were Korea, but for anything more specific you'd have to contact Customer Service.