Centaur and Harvey Comics liked doing text stories in their comics, often featuring characters that starred in strips. So, most of the text stories are coming from these companies. Speed Comics was an anthology title, originally starring Shock Gibson in a slightly different form. Eventually, he was joined by Captain Freedom (who edged him out of the cover spot) and the Black Cat. The covers would often be by Simon & Kirby or Alex Schomburg and as often the case were often more interesting looking than the actual stories inside. Especially Schomburg who specialized in providing all-star jam-packed action on the cover, showing the heroes all together in climactic battle with the enemy. At other companies, readers usually just had to wonder exactly what was the adventure behind the cover, making it up in their heads. Not so at Harvey! In the text stories, they started providing a little feature called "the Story behind the Cover".
Here's one such from Speed Comics #34, 1944. The whole comic can be read at http://www.goldenagecomics.co.uk. Enjoy.