OK. The C140s is a mid range model with high quality laminated back and sides, probably not worth a great deal, especially if its in poor cosmetic condition, maybe £400 here in the UK. The AST100 was slightly higher in the range, but not at the top, beneath the John Mills models, equivalent to the A10, but with different bracing. May have been all solid, I'm not sure. Slightly higher in value maybe £600.
1969 Rokutaro Nakade A9
1966 Sakazo Nakade model D
1977 Aria AG80 (Masaru Takeiri)
1988 Hiroumi Yamaguchi SS