Hi Joyce,
Angelbeck is a part of Löningen, there some Dettmar addresses not Detmer:
Dettmar, Bernard,Tannenbergstr. 41, 49624 Löningen
Dettmar, Georg, Corveystr. 22, 49624 Löningen
Dettmar, Georg Friseur(hairdresser), St.-Annen-Str. 1, 49624 Löningen
Dettmar, Gustav KfzMstr.(car repearing), Linderner Damm 5, 49624 Löningen
Dettmar Bernard, Wismarer Str. 17, 49624 Löningen
There also a Deters on the Angelbecker Street:
Deters, Werner, Angelbecker Str. 44, 49624 Löningen
The border to Emsland - former Kingdom of Hannover - is not far, about 15 miles.
The emigration book of the "Kreis Lingen", now Emsland, listed not Detmer or Dettmar but this:
Gerd Heinrich Deiters, born 2.Sep.1810 Drievorden, County of Bentheim
Parents: Johann Henric Deiters and Catharina Schulten
emigrated 1839.
Also 22 Beckmann, but only a Anna Maria Beckmann, born 5.Sept.1835, emigrated 1852 via New Orleans
The south part of the Oldenburg province (Löningen included) and Emsland was former about 98% catholics, by the Prince Bishop of Münster.
Good luck,
Werner