Ive just put my Kasuga archtop on ebay, please have a look its a beautiful guitar to look at and to play its even better.
i couldnt find an official age or price for the Kasuga (one member here said tho that it could be early 70s) the price ive put it on evilbay for is a price that i would feel comfortable to let it go for.
good luck, and happy bidding