First off, having seen a bunch of Jazz Sounds, I'm almost certain that it is an authentic Tokai.
Yours predates when they started printing the serials onto the headstock, so I'm guessing late 90's or 2000's TJB-45. Is there a serial on the neck plate?
The older ones had a little sticker at the heel that designated which version they were, and the newer ones often have a clear sticker that says "Made in Japan" if they're a Japanese Tokai.
It's not a surefire way of knowing if it's authentic or not, but if you take off the neck, often you'll find some writing in the pocket or on the back of the heel that will have the model number. Also, every Tokai bass I've ever seen has a Phillips truss rod, rather than hex.
If I were you, I'd take off the neck anyway, just to see if I had a solid-wood or laminate Jazz Sound, since the cheaper ones in the early 90's had ply bodies.
Caps & pots won't really tell you where your bass was made. My 80's Tokais used pots and caps made by different manufacturers, and although I don't know what the Korean ones use, I can tell you that there are still companies like Mitsubishi making caps and pots in Japan (since I've bought them at the ESP Custom Shop in Osaka).
But, if you like the way it plays, and you like the way it sounds, who cares where it was made? It might be Japanese, it might not. Don't buy into that hokum about where/when something was made.