I have a book with me today which I LOVE.If you have other names in the Frederick Co., MD area this is a great book to own and is available for sale at the historical society and other places:
"Pioneers of Old Monocacy, The Early Settlement of Frederick County, MD, 1721-1743" by Grace Tracey & John Dern. On page 287 there is information on an Abraham Miller who owned land in the area of present-day Lewistown.He and his wife Frances had at least 5 children before his death in 1754.The authors state "Frances was a 'Protestant Dissenter' who would affirm but not swear, (as executor of her son Christian's will) married a Shelhorse as her second husband.There is muchrequired work remining for the genealogy of this family."
The footnote mentions Frederick County Administrative Accounts, A1:169; says his (Shelhorse) given name is not stated.There were no other similar names in the index of this book; also no Haynes.
Your husband has an interesting story.I would like to know where the farm was.That area has grown considerably in recent years. Housing developments springing up on what were farms.I know a few people who grew up in that area, I might be able to get some information that way.
I will check the other books I have on Frederick County.You might want to write the Frederick County Historical Society which is on Church Street.I don't know the zip code.They have many books and many genealogies on local families submitted by embers and others.I will get back to you.