Well, I'm discovering what a moron the previous owner of my bike is. Since I have it running now, I'm paying attention to everything about the bike. Newest thing I discovered was that the rear brake wasn't working very well and that I could roll the bike backwards with the brake pedal pressed all the way down. So, I went and looked at the brake and discovered that the last time the rear tire was off, the brake assembly wasn't put back into place properly. Looking at the pictures you'll be able to see what I'm talking about. Guess I know what I'm doing this weekend.
I have to say that this is the kind of obvious detail that should have not passed when you purchased the bike (if you have seen it before) You should have controled the brakes before riding it, brakes are life saver. On one point we agree, the previous owner is a complete moron, hopefully it seems in better care in your hands now
Got the rear brake fixed. Had to remove the axle to be able to get the brake into it's proper place. Found another issue while doing this. According to my repair manual, the nut for the rear axle should be on the right side. Mine was on the left. Don't know if it is a big deal or not, so I went ahead and got it back how it should be. Other than that, the bike is running pretty well, just need to tweak the carbs and then call it good.
This is probably not a big deal, but certainly makes sense considering what else you've found. Hopefully that's the last thing you find messed up!