1947 - 1960s
Amerpol Records was the label of Amerpol Enterprises Inc., founded in 1947 and still active (see http://www.amerpoltravel.com). The records were produced until early 1960s, both 78 rps (mostly reissues) and some LPs.
However number of copies was probably limited, thus all these records are hard to find now.
Source: Russian Records