You might also consider slowing down and taking some time to read and learn. You don't have to buy a watch in the first week you are looking. Patience is very important with vintage watches, it's not like you can just walk into a store and buy a commodity. Each watch is different, each seller is different. Go slow, learn, and wait for something good. Over time, you will learn the answers to all of your questions. In fact, if you take the time to read through old threads on this forum, you will find an incredible treasure trove of information.
You will save yourself a lot of time and disappointment in the long run if you take the time to learn what you really want. Did you see the photo I posted in your other thread? I bought a 168.024, but then decided I preferred a 165.010, and then I decided I preferred the 166.009. Then I found a better 168.024 and then a better 166.009. And then the better 168.024 stopped working. And so on. And that doesn't even include the 168.022s and extra bracelets that aren't shown. Don't be like me, look at all the extra crap I have lying around now.