1) The Story of Baseball and Football
2) The Wright Brothers
3) Prehistoric Beasts
4) The Great Explorer
5) They Served the Nation
In their natural, folded, state, the comics measure 4 3/8" x 2 1/2" and there are 16 pages counting the cover. The comic is made of cheap pulp, which comes as no surprise As you can see below, they are prone to a slight diamond cut and the centering is quite off, a phenomenon I have observed in scans of other numbers:
Custom Comics was a division of American Comics Group and was the only thing left when the parent company folded up all other operations in 1967. They had a familial, capital and distribution tie in with National Periodical Publications, better known today as DC Comics (although it's now part of Marvel--heresy to those of use born in the 1960's!). Custom Comics published bespoke comics from 1954 until 1977 according to the Grand Comics Database. The database has 27 titles published by Custom Comics but does not list the True Fact series. The piece above has to date from 1966-77 because, as all of my faithful readers know, the "curved-t" Topps logo debuted that year and lasted until 1980-81.
There is a little bit more information inside. Here's an interior shot:
The indicia at the bottom left of the left page reads:
So the copyright belonged to Topps, which I find interesting.
I found a scan of three other books and already had one of #1, so might as well show the others here to keep them all in one easy spot:
Clearly the format is the same for each number. While the series may be complete at five, the year and method of issue remains an open question. Benjamin states it was confirmed they were a retailer item, but for what purpose is hard to fathom. Most Topps retailer bonuses were certificates that could be accumulated and put toward consumer items. What retailer would want some undersized comic book?
Benjamin also has the same five subjects listed. As for the year, I have a note somewhere it was 1974 but since I can't find the reference anymore, I can't say how correct that is. I also recall there being some commentary somewhere years ago that these were a reissue of an earlier edition. I'll put that in the hearsay category until further information is developed.