As well as including in each box set, the rules were sold as a separate accessory with the score determinator, as pack TC-K.
The rules changed significantly between the flat and 00 scale eras, as the game adapted to the new playing pieces. How you were caught out, how runs were measured, and the method of run-outs all changed.
The rules leaflet changed colour from the Card set (below left) to the Celluloid and Display editions. These are shown side by side in the middle image below and are actually identical in places, but with updated images of the new style players and rules changes to accommodate the 00 scale game pieces.
A major redesign came in the early 70s to the predominantly white leaflet many of us will be familiar with. The last design change, in the late 70s, heralded the blue rule book with an illustration looking very much like Gordon Greenidge.
Below you can follow links to the full rule books page by page for the four different designs. Click on the images to enlarge.