I, too, would like to see the source for Thomas Marston marrying Elizabeth Marvel, if it's available. I don't have the source for my information, either, unfortunately, but have handed down information which shows the marriage to Elizabeth Marrell in England.
I suppose there is the remote possibility he may have had a wife in 2 countries, but I know he died in Worcester, Worcestershire, England, and that he had the following 6 children in Worcester, Worcestershire, England: Elizabeth b. 1682; Mary Ann b. abt 1684; Martha b. abt 1687; William b. abt 1690; Joseph b. abt. 1693; and Benjamin b. abt 1696.
His daughter Elizabeth, b. 1682, is my 6th gt. grandmother. She married Samuel Snell 3 Dec 1702 in Worcester, England. Their daughter Hannah b. 1723, St. Helens, Worcestershire, England, is my 5th gt. grandmother. She is also famous as a female soldier. Articles and books have been written about her. Check out http://www.hannahsnell.com/
Wouldn't a double life with lots of children in 2 countries have been unusual in those days? Would love to solve this mystery.