Lewis Nathan married Hannah Cohen (daughter of Moses Cohen) at the New Synagogue on 15 Aug 1838. They lived at 3 Cobbs Yard. Both gave the same address but this was very usual as it saved a little on the registration fee for the marriage. It did not necessarily mean they were living together before the marriage but it didn't mean they weren't! The New synagogue moved in 1838 to Great St. Helen's Street.
I cannot trace a marriage of Moses and Rebecca but I will keep it on my list of things to look at and let you know if I find out any more.