I have some problems with compact guns, but have found a few that fit nicely. I use the pinky extension on all of my magazines because I have big hands. Overall, it is my EDC and I get it out to practice. I think you should try some different guns to see how they fit. To me, it's the grip.
Everyone who ever buys a NEW gun gets a box and manuel. So what. You just bought an old model, for what reason. Did you get it to look at or use? As for investment, you may have just paid for someone elses investment. The big question about buying old stuff as investments is can you convince...