I only have two Masakuni concave cutters, one from the 90s and the other bought in 2014. Although both are 8" cutters, the constructions are somewhat different. The old one is heavier and the handles are broader near the rivet than the new one.
The old one has a chip but still cuts well using the unchipped portion of the cutter. Masakuni is expensive but very good, you would love using them. My other tools are Yagimitsu, and I like them too.

The old one has a chip but still cuts well using the unchipped portion of the cutter. Masakuni is expensive but very good, you would love using them. My other tools are Yagimitsu, and I like them too.

