New Bedford whaling files (seamen's insurance records) show an Edward Remington, age 12, b. Dartmouth, MA, who went on a voyage 19 May 1847. The age and birthplace could easily match Joseph's son "Edmund." It says he was 4'10" and had a light complexion, brown hair, and blue eyes.
In the Federal Census of 1850, there is an Edmund C. Remington, age 35 MA, living at Reading, Hillsdale Co., MI. He is a carpenter. This could be the son of Joseph & Mary.