This one I like a lot. It has Mars. It has stars (thanks APOD). It has a rocket (amazing what you can do with a lava lamp and image editing software). It looks hand drawn thanks to various graphic filters. And it has the right 1930s look, I think, maybe more detailed than a real magazine of the period but it'll do.
I think I may change it to
Forgotten Futures XI: Planets of Peril
Roleplaying in the worlds of Stanley G. Weinbaum's 1930s Science Fiction
Makes it clearer that it's based on Stanley Weinbaum's SF, not 1930s SF in general.