Heisey examples are sometimes found with Pairpoint's Harwich engraving on it.
The set is comprised of the #301 base and the #300 two light arm with the #300 bobeche and the #9 "A" prisms.
Heisey made this candelabrum from 1924-1957. Heisey colors include crystal, alexandrite, sahara, and cobalt. It was made in several parts, and was also available in combinations of crystal and one of the other colors. It was also available in a 3-light version. Occassionally marked in the constriction at the base.
This information comes from The Collector's Encyclopedia of Heisey Glass 1925-1938 by Neila Bredehoft.