One key that helps on some of the duplicate shows is that the last name of the family changed from Cugat to Cooper sometime between December 1948 to January 1949.
There is a good log at http://www.lucylibrary.com/pages/mfh-guide.1-13.html
48-07-05 (aud) The Cugats Tenth Wedding Anniversary was 48-08-06 (003) The Portrait Artist
48-07-05 The Cugats Tenth Wedding Anniversary was 50-04-16 #84 10th Anniversary. Liz's name is Cooper.
48-07-23 - 001 - Literary Club's speaker comes to Dinner [inc].mp3 was 49-02-04 (030) Speech for Civic Organization
48-07-23 Literary Club's Speaker Comes to Dinner was 48-08-06 (003) The Portrait Artist
48-08-01 (02) Kissing Booth was 48-08-13
48-08-20 #5 Liz Teaches the Samba was 50-02-17 Liz Teaches the Samba. Liz's name is Cooper. Also, the bank manager's name is Forsythe in the 50-02-17 episode, but Kimbrough in the 48-08-20 episode.
48-10-02 (011) Young Matrons League Tryouts was 48-10-16 (013) Young Matrons League Play. Starts off with Liz saying she has cotton in her ears.
48-10-03 (or 48-10-09) #12 George's Old Flame was 50-04-16 #84 10th Anniversary
48-12-25 (or 48-12-26) Numerology was a 24:46 edited version of 50-05-14 Numerology.
49-01-01 (025) Young Matrons League Tryouts was 48-10-02 (011) Young Matrons League Tryouts
49-05-13 #44 Anniversary Presents" was a duplicate of "10th Wedding Anniversary 012 481003".
50-03-05 #78 "Women's Rights -part 1 " was a duplicate of "Gum Machine #039 490408".
50-04-16 (084) The Cugats Tenth Wedding Anniversary.mp3 was 49-05-13 (044) 10th Anniversary Presents (AFRS) Begins with Liz singing Here Comes The Bride.
51-02-02 The Two Mothers-in-law was 490117 027 Piano and Violin Lessons