[1] In the late 1950s Mollo was approached by Kevin Brownlow for assistance regarding the development of his film It Happened Here.
Initially, he was to advise on German uniforms but became so interested in the project that ended up co-writing, co-directing and co-producing the movie.
Mollo's uniform expertise led him to create Historical Research Unit with his brothers.
In the early 1970s Mollo wrote a number of books on military history and uniforms.
As a German-uniform consultant Mollo advised on films such as The Eagle Has Landed (1977), The Pianist (2002) and Downfall (2004).