Frank Holton, though not an instrument maker himself, expanded his company to manufacture instruments which was his occupation until retiring at age 80. ДЇrank Holton's wife Florence was a music teacher. York and Sons before Holton established his own company in 1898. In 1885 he had partnered with James Warren York in York & Holton, York's successor to the instrument maker Smith & York which became J.W. By the time he was 34, Frank Holton was an accomplished trombone player and principal trombone of the Sousa Band, a role that would later be filled by Arthur Pryor. Holton was born Main Allegan, Michigan to farmers Otis (b. Founded by Frank Holton, a trombone player in 1898 in Chicago, Illinois, the firm built brass instruments in Elkhorn, Wisconsin from 1918 until 2008 before moving all current production to Elkhart, Indiana and Eastlake, Ohio. Holton is a brand owned by Steinway Musical Instruments' Conn-Selmer division. The second character indicated the month of the year 'A' for January, 'B' for February, 'C' for March, etc. In March of 1974 an alpha-numeric system was established: The first character of the serial number indicated the decade 'G' for the 1970's, 'H' for the 1980's, etc. There aren't a lot of Holton models worth mentioning, so no jump station.

The example I have below is the only other one I've ever seen. I've only heard of two baris - and one was a recent (well, 1960ish) horn.

Holton serial number chart