National/Prize

 What was the deal with National (DC) Comics and Prize Comics in the 1940's?  As seen here, the latter company, publishers of Yank and Doodle, The Black Owl and Dick Briefer's Frankenstein, regularly advertised in DC mags and yet there seems no obvious tie-in between the two companies. The later ACG was, in fact, a secret DC company but I find no evidence to indicate any connection with Crestwood's Prize and National. Anyone?