I have a Pro Max LH that has a worn down pawl. I gambled when I ordered a Pro Max compatible pawl from ereplacementparts, but its too big.

 

I can't figure out what model number I have either. After taking it apart and looking everywhere on the reel I see the numbers "1910" next to the gears and "LH 1911" inside the handle plate, "LH 1912" in the brake plate. There was a sticker with letters and number underneath the rod seat but they didn't match up with anything on the Abu website nor ereplacementparts. 

 

Are there any tricks that distinguish the different models?

Manufacturers including Abu stamp a number on the bottom of the reel foot that designates the model number of their reels.  I suggest you call Abu Garcia service with that info and they will send you the correct part - usually at a cheaper price than second tier suppliers charge.

 

The "Pro Max" reels have been around for 40+ years and there are many different models.  You can order parts from the reel schematic if you have one.  If you call Abu, I'd suggest asking for one if you don't since it's a handy way to identify a part you might need even if you don't know what the part is called.  Please send me one of those "thingamajigs" just doesn't hack it.