Be careful when buying this kind of piano. There are many things to decorate. You'd better find a professional to choose, or you will be fooled unless you have money! The following are the main models and corresponding years of Yamaha. I want to buy a second-hand original Yamaha piano, 13000 yuan, which must be broken before the 1960s, otherwise it is a passive piano, and the models are all in the upper right corner of the steel plate:

Release year factory serial number main model

1946~ 1954 40000~49999 100 200 300

1954 ~ 1959 50000 ~ 89999 u 1a u 1B u 1C U3a

1959 ~ 1965 90000 ~ 299999 100d U2a U2B U3B U3C U3D

1965 ~ 1970 300000 ~ 8 19999 u 1E U2C U3E

1970 ~ 197 1 820000 ~ 979000 u 1F U2F U3F U5C U5B

197 1 ~ 1972 980000 ~ 1 149000 u 1G U2G U3G

1972 ~19801kloc-0/50000 ~ 27999u1u2u3u5u7uuxw system.

1980 ~ 1983 2800000 ~ 3479999 u 1M U2M U3M YUS YUA YUX

1983 ~ 1987 3480000 ~ 4209999 MC 10 1 MC 20 1 u 1A U2A

U3A UX- 1 UX-2 UX-3 UX-5

1987 ~ 1990 42 10000 ~ 4679999 MC 10 bl u 10 bl u 30 bl UX 10 bl

UX30bl UX50bl

1990 ~ 1994 4680000 ~ 5 189999 MC 10A u 10A U30A

UX 10A UX30A UX50A

1994 ~ 1997 5 190000 ~ 5459999 MC90 u 100 U300 u 100

UX300 UX500

1997 ~ 2000 5460000 ~ 5809999 ym 1 Yu 1 YU3 YU5

2000~ now 5810000 ~ ym10ym1yu10yu30yu50.

I hope it helps you! !