There is a verse that comes between verses 4 and 5 above, which I half-remember from the album "Spike Milligan and Jeremy Taylor - An Adult Entertainment", live at Cambridge:

Old she was to be having a kid,
the pain of it drove her mad, it did.
???????????????????????????????????
"Oh, sod it", Ethel shouted, "oh, sod the kid!"

Also, I seem to remember line 2 of verse 5 above being instead:

"....like chitlins tied with a piece of string...."