Dave,
HHL is not an open mold. It was used by both Tom Haines and Christy & Jones. I think it was owned by C&J. One edge spot is unusual but not unknown. The cost of a chip is sometimes set be the amount of labor to produce it. One edge spot is less expensive then six. Many companies have used another distributors mold until they had there own made. Usually the owner of the mold receives a small commission per chip.
jim