There was an earlier Strad-O-Lin thread, which I'm too lazy to look up, that discussed possible manufacturers of their mandolins. Two firms mentioned, both in the New York City area I believe, are Hoverick Bros. and Homenick Bros. The very similar names probably mean that it was one or the other, and apparently no one's sure which. John Bernunzio once advertised a Strad-O-Lin that he said was built by Hoverick Bros., but with names so similar, it would be easy to mix them up.
Gibsn: '54 F5 3pt F2 A-N Custm K1 m'cello
Natl Triolian Dobro mando
Victoria b-back Merrill alumnm b-back
Stradolin Vega banjolin
Sobell'dola Washburn b-back'dola
Eastmn: 615'dola 805 m'cello
Flatiron 3K OM