Second, good advice about checking early sources - more than once. It's something I spend a great deal of time doing, and I appreciate the work of others who have and are kind enough to share their findings.
Third, a bit of info on Mordan, a UK company:
Following Sampson Mordan's passing in 1843, the business continued in his name, run by two of his sons, Sampson Jr. and Augustus, with another of his sons, Francis, forming his own company, F. Mordan and Co., which specialized in making both gold and silver pens and pen holders. Even with his involvement in the business lasting just 21 years, Sampson Mordanís legacy has lived on even today, with much of his work highly regarded in the antique market.