The 37 can be a bitch to reassemble if you aren't familiar with it!
??
Not really - actually it's one of the easier ones.. A model that can cause the most pious of owners to use words that would make a sailor blush is the Browning BPS..
As to 'complicated', the Browning A-5 (and clones) probably takes the cake - but paying attention to the disassembly will pay off..
Rock on, dudes..