Johnas:
You lathe was a Sebastian/May lathe. Here is a little history.
Sebastian/May formed in Cincinnati, OH in 1882
Moved to Sidney, OH in 1890
Sebastian formed 1891
Sebastian sells out interest in Sebastian/May in 1892
May sells out to A.P. Wagner 1894 (mainly produced wood & pattern lathes)
Sebastian moves to Covington, KY 1896
Sebastian sells out to Sheldon 1955
Sebastian produced lots of lathes up until they were bought by Sheldon, so that Sheldon could have a gearhead lathe line. A lot of the old Sebastians were produced for WW2, they will have an old flaming ordinance bomb, or a Navy anchor after the serial number, signifying they were accepted for government service.