LionelZona,
Lionel HO trains were made or partially made overseas during 2 periods of production, 1957 - 1966 & 1973 - 77.
The first HO trains were licensed through Rivarossi in 1957 & later through Athearn.
Dies & Tools were later purchased from John English - Hobbyline for domestic production.
HO was dropped in 1967.
In 1973 HO was reintroduced by Lionel, with production divided between domestic partial production at the Mt Clemens Plant & overseas partial production by Kader(Bachmann) in Asia.
HO was again dropped from Production in 78.