Finding 1930s vintage or reproduction men's pants size can be difficult. However with the right modern pants you can approximate the 1930s look.
SF's first fashion icon: Levi's 501s
Zoot suit - Wikipedia
New 1930s Style Men's Pants Mens wide leg pants, High waisted trousers, Vintage mens fashion
Original 1930s British Men's Striped Morning Trousers by 'P. Ltd
The Contemporary Man:. 1930s Menswear Fashion
New 1930s Style Men's Pants Jodhpur pants, Pants for women, Pirate dress
Red Tornado Ground Crew Trousers 1930s Style Mens Tapered Cargo Pants Dark Khaki
1930's men's slacks or 'swing trousers
Men's Fashion: 1930s/40s-->1950s Fashion and Decor: A Cultural
New 1930s Style Men's Pants
New 1930s Style Men's Pants
New 1930s Style Men's Pants Mens slacks, 1940s mens clothing, High waisted slacks
1930s Men's Fashion Guide: Style & the Pragmatic Decade