This episode is a continuity nightmare. The one thing I'll point out is in this one, Blanche's maiden name is Somers, like her real last name (Brett Somers). In the ep where she was getting remarried, her maiden name was given as Jefferson.
Lt. Unger is performing a barracks inspection, and Pvt Madison is wearing a backwards baseball cap instead of the correct military headwear. Unger asks "Is that a regulation hat" and Madison says " For the NY Yankees it is". A side shot shows the cap has a NY Mets logo, an orange NY. Also, the cap is the wrong shade of blue for a Yankee cap.
Felix's ribbons indicate service in Vietnam - highly unlikely given the time frame of the flashback.
In the flashbacks at the military barracks, all of the men have 1973 hair cuts.
Although listed in the closing credits as Captain Wyatt, Liam Dunn is referred to as Colonel Wyatt by Felix at Oscar's wedding 16 minutes into the episode and he (Dunn) turns up in a Colonel's uniform in his scene.