The Spinners version of "Dip and Fall Back" is on thread 101959. Date 1970s (on a 1973 disc).
Dip and Fall Back

The Mento song seems to have appeared in the 1960s; in any case, the one with a similar tune to that used in "Matilda."
It was recorded by Lord Power, The Hiltonaires (Ska version) and Lord Fly with the Mapletoft Poulle Orchestra.

The lyrics suggest a possible post WW2 date, but I can't find any recordings from the late 1940s-early 1950s.