Apart from Frankie Howard, Lance Percival is the only other actor to appear in all three "up" films.
When Lurk is trying to write a poem, there are two literary references. He parodies "The Soldier" by Rupert Brooke and mentions the novel, "All Quiet on the Western Front", by Erich Maria Remarque.
Frankie Howerd's characters in the three "Up..." movies all have similar names. Howerd is Lurcio in Up Pompeii (1971), Lurkalot in The Chastity Belt (1972) and Lurk in Up the Front (1972).
Frankie Howerd also starred in two other cinema movies with the word "Up" in the title separate from this series which included Up Pompeii (1971) and The Chastity Belt (1972). The other unrelated "Up" films were Further Up the Creek (1958) and Carry on Up the Jungle (1970).