Complex sentence: Thirty-seven of the 41 overall Mulliner stories were originally published between 1926 and 1937, but the final four stories appeared much later, being published in widely-spaced intervals between 1947 and 1970.
Split into simpler sentences: Thirty-seven of the 41 overall Mulliner stories were originally published between 1926 and 1937. The final four stories appeared much later, being published in widely-spaced intervals between 1947 and 1970.