I think I may have found mention of Fr. MAHER in the biography of a Carmelite priest, Fr. Anastasius SMITS. The article says a Fr. Peter Thomas MAHER met Fr. SMITS in Cumberland, MD and discusses the intriguing circumstances of Fr. MAHER's transfer to Prince George's County. It's all on page 3 of the document.
Here is the link: http://carmelnet.org/necrology/obits/SmitsAnastasiusJ.pdf
I live in Prince George's County, about 1/2 hour drive from Upper Marlboro--if there is something I can do for you here, let me know and I will try to help you.