Updated:
A few things concern me about 1941 - low income, luck playing a big role, and the Axis advantage. Here are some house rules that can help improve the game IMO.
IPC x2
IPCs will be x2 (not territories). The purchase capacity will remain the same, but now players have more money to purchase higher priced units.
Re-Roll Tokens
Each side will receive 2 re-roll tokens to re-roll a round of combat. This will be used especially in cases where the dice are really bad during a crucial battle.
Additional Infantry
Allies receive an additional infantry per IC. Axis receive 2 additional infantry per IC.