Everyone, including Archie, Edith and Fred must've forgotten that they've reunited last season in "The Brother"! In this episode, they say the last time they've met was at Archie and Edith's wedding where Archie punched Fred and broke his tooth--which is the same story used in "The Brother"! Had the writers ran out of ideas and decided to repeat an episode and figured none of us will remember it?!
Edith says that Archie is 55 yet in "Flashback: Mike Meets Archie" (which was 8 years ago), Archie says he's 49. And he said that in a flashback where Mike and Gloria was dating so it takes even a bit more than the show first started! That's over 9 years! So Archie should be 58-ish not 55.
Katherine: I'm Mrs.Bunker.
Stephanie: No you're not. (slams the door)
Katherine (to Stephanie): How old are you?
Stephanie: I'm ten.
Edith (to Katherine): How old are you?
Fred (on the phone with Katherine): Hey, sweetheart, darling. How's my little pussycat?
Archie to Walter: Get a load of this over here.
Walter: Why won't you try it?
Archie: You think I should?
Archie (on the phone with Edith): Hey, sweetheart. How's my little pussycat?
Walter: What'd she say?
Archie: She hung up the phone.
Edith: Oh, I'm not the one who knocked his tooth on our wedding and then didn't talk to him for 29 years. Oh, no, no, no. I'm not mentioning no name, I'll just look at the person and whistle.
Edith looks at Archie in the eyes and whistles
Archie: You know, that's the stupidest thing I've ever heard.
Katherine: I'm eighteen.
Edith drops her plate on the floor in shock. She shakes her head and picks it up.
Stephanie: What grade are you in?
Edith drops her plate once again in shock.
This episode was videotaped on February 09, 1979.
When Edith looks at Archie and whistles, making an obvious reference to Archie, it's the exact same thing that Archie does when he wants to refer to Edith in previous episodes, such as Ep.200 "Stephanie and the Big Crime Wave"