Book 38: Really Useful Engines, by Christopher Awdry, Random House, 1983. Preschool to elementary.
We came to the end of the wonderful Thomas the Tank Engine Collection stories and my little Thomas wanted more. I wasn't ready to plunge right back into the collection again and start from the beginning, so I found this little book.
It only has four stories, and it is "based-on" The Railway Series by Rev. W. Awdry, but unlike most of the "based-on" Thomas book, the author did an excellent job of keeping the feel of the original -- probably because he was Rev. Awdry's son.
The illustrations are wonderful, and again, have the feel of the original without attempting to copy them.
All in all, it has been a really useful little book.