Notes: "The Omega slide adder was made in Hong Kong, and was one of the nicer copies of the Addiator design. The design of the exterior of the Omega was copyrighted by T. H. Ramsey in 1964. The Omega adders (there was also a 6-column version) may have been made for a company in Campbell, California called Wescosa. Some are marked “Made exclusively for Wescosa”. "
