Complex sentence: In 1783 he also held a position as an agent working with Sir Nathaniel Wraxall, and was noted since this time for being very wealthy, probably from his secret parliamentary pensions he was receiving.
Split into simpler sentences: In 1783 he also held a position as an agent working with Sir Nathaniel Wraxall. And was noted since this time for being very wealthy, probably from his secret parliamentary pensions he was receiving.