Hi Dave, I really know nothing about your particular model of Kasuga. I can tell you Kasuga acoustics were generally entry and intermediate level guitars. They were imported into the US under the Conrad brand name. I do have a Conrad catalog that shows a $1,100 Kasuga but most of the guitars list for between $250-$600.
Besides fancy inlays, your guitar's value is going to be determined by the wood used in construction. If your Kasuga is plain and made of laminate, expect a value around $175-$275. You can check the top by looking for grain on the inside edge of the soundhole. If it's laminate you'll see layers rather than grain. Check the sides and back by comparing the wood grain on the outside with the wood grain on the inside. If the wood is solid the grain should match.
If you discover your Kasuga is made with a solid top and laminate sides which is typical of the intermediate level instruments, price will move up to $300-$400 or more depending on the inlay work.
If you discover your Kasuga is made of solid top and sides you have something. I'm not sure Kasuga produced a solid top and sides guitar but who knows..
Let us know what you find.