Beaman's Washington County Births from Death Records lists Roby as Rhoda. The source is cited as NK Marriages 4-34-35. Beaman's also has the following Albert C. Gardiners listed: Albert Clarke Gardiner of Randall and Hannah, b. 1825 Exeter. Albert Clarke Gardiner of Jesse and Elizabeth, b. Jan 1826, NK Albert C. Gardiner of William T and Nancy (Hazard) Gardiner b. Apr 1831 NK. Any of these Albert C's are the right age to have been the parents of the Albert born 1854. He is shown in the 1880 census with wife "Delia D." living in NK. No children are listed.
Don't get too discoruaged. Gardiners are tough because they used the same names over and over...I got lost in a sea of Samuels when I tried to find my line. It took a while but I did it! I have some other sources I can check to see if Albert shows up in any of them.