The following list of numbers represents the date of manufacture followed by the piano serial numbers. The letters ‘sn’ mean serial number.
Piano Manufacturer: Hardman
1900 sn-48000 1922 sn-89300 1935 sn-95200 1960 sn-121100
1905 sn-58000 1923 sn-90000 1940 sn-97000 1966 sn-134300
1910 sn-68100 1924 sn-91000 1947 sn-101000 1973 sn-144700
1915 sn-77200 1925 sn-91500 1952 sn-106400 1980 sn-151100
1920 sn-86000 1930 sn-94200 1955 sn-109000 1982 sn-152200
Piano Manufacturer: Harrington
1900 sn-24500 1922 sn-93000 1935 sn-118000 1956 sn-164200
1905 sn-32000 1923 sn-96000 1940 sn-130000 1957 sn-165000
1910 sn-43000 1924 sn-99000 1947 sn-151500 1958 sn-166000
1915 sn-70000 1925 sn-102000 1952 sn-158600 1959 sn-166723
1920 sn-88000 1930 sn-105300 1955 sn-163200 1960 sn-167125
Piano Manufacturer: Hazelton Brothers
1900 sn-25800 1922 sn-215000 1935 sn-274000 1950 sn-408000
1905 sn-37600 1923 sn-223000 1940 sn-289000 1952 sn-416000
1910 sn-49000 1924 sn-230000 1947 sn-401000 1954 sn-427000
1915 sn-64000 1925 sn-237000 1948 sn-403000 1955 sn-503000
1920 sn-73000 1930 sn-266000 1949 sn-406000 1960 sn-511000
Piano Manufacturer: Hinze Made By Kimball
1904 sn-55000 1918 sn-96500 1932 sn-132000 1947 sn-503000
1905 sn-55000 1919 sn-100000 1934 sn-132000 1948 sn-504000
Piano Manufacturer: Horugel Germany
1900 sn-8800 1922 sn-34750 1932 sn-43180 1948 sn-40800
1905 sn-11150 1923 sn-35200 1933 sn-44000 1949 sn-44630
1915 sn-28950 1925 sn-37500 1935 sn-43380 1951 sn-44900
1920 sn-32500 1930 sn-42500 1940 sn-44000 1952 sn-45100
Piano Manufacturer: Horugel Samick Korea
1976 sn-00645 1977 sn-00847 1978 sn-30150 1979 sn-32740
Piano Manufacturer: Howard Built By Baldwin
1900 sn-9000 1922 sn-145000 1935 sn-251800 1950 sn-443258
1905 sn-31000 1923 sn-154000 1936 sn-260000 1951 sn-468177
1910 sn-57000 1924 sn-162000 1940 sn-300000 1960 sn-496180
1915 sn-83000 1925 sn-172000 1948 sn-402000 1965 sn-825030
1920 sn-12700 1930 sn-217000 1949 sn-431000 1968 sn-106212
Piano Manufacturer: Hyundai
1978 sn-30150 1981 sn-31960 1984 sn-50630 1988 sn-114390
1979 sn-32740 1982 sn-39410 1985 sn-53844 1990 sn-380000
1980 sn-29530 1983 sn-53400 1986 sn-75020 1995 sn-500000
Piano Manufacturer: Irwin & Sons
1960 sn-158800 1962 sn-169000 1964 sn-183000 1966 sn-207000
1961 sn-163000 1963 sn-176000 1965 sn-195000 1967 sn-219000
Piano Manufacturer: Ivers & Pond
Grand Pianos Ivers & Pond Numbers:
1900 sn-24000 1922 sn-71000 1935 sn-78400 1950 sn-84000
1905 sn-37800 1923 sn-72100 1936 sn-78600 1955 sn-86350
1910 sn-48100 1924 sn-73200 1940 sn-79900 1960 sn-91014
1915 sn-57900 1925 sn-74500 1946 sn-80000 1962 sn-94370
1920 sn-68900 1930 sn-77500 1947 sn-80300 1963 sn-97026
1960 sn-91014 1966 sn-109800 1972 sn-127200 1978 sn-144000
1961 sn-92222 1967 sn-112300 1973 sn-130700 1979 sn-145600
1962 sn-94371 1968 sn-116000 1974 sn-135600 1980 sn-148000
1963 sn-97026 1969 sn-120000 1975 sn-137500 1981 sn-150500
1964 sn-100442 1970 sn-121900 1976 sn-140900 1982 sn-145300