I was just re-watching the third and fourth series on netflix (Hey! How about Series 1,2, and 5?) Anyway, i've seen just about all of the episodes numerous times, but I cannot recal which episodes(s)contained Jeffrey as "Fat Boy Higgins". The individual synopsyses (synopsyii?) on IMDb did not contain this information .. I was wondering if netflix had left out that episode, or if it was in a different series (season).
Season 5, Episode 4: Diana's Diet
29 September 1994
Diana's foot shows no sign of healing and Tom is anxious for her to see a doctor. For all of her brash facade she is reluctant to seek medical advice in case she is given the worst possible scenario. However,she complies and is told that she has diabetes and must alter her diet. A relieved Tom proposes. Baines also proposes to Jane,in order to get his golf club membership, but she turns him down.
www.imdb.com/title/tt0743310/
At least I believe that to be the correct episode based on the information you gave. Hope this helps!
"It's a real burden being right so often." Captain Malcolm Reynolds, Firefly