Welcome to OF, Kiwi76. You did well by coming here and asking for help evaluating prospective purchases before you pulled the trigger. Too often we see new enthusiasts who have rushed into a purchase and are now stuck with poor examples of vintage watches purchased at inflated prices that they can't return for a refund. A few pieces of friendly advice. First, slow down. There will always be another desirable watch for you to purchase. Second, stick around and read every thread on OF that relates to the type of watch that interests you (use the search function to find relevant threads). Third, if it's a vintage Constellation that you want, read everything on this site:
Omega Constellation Collectors (omega-constellation-collectors.blogspot.com) Fourth, watch all the videos about vintage Constellations posted on YouTube by The Omega Enthusiast. Note: He has a very nice selection of authentic vintage Omegas for sale on his website, but the prices are very high, so best to shop elsewhere unless price is of no concern to you. Fifth, check the private watch sales forum on OF frequently:
Private Watch Sales | Omega Forums Authentic, original vintage Constellations and other Omega models come up for sale all the time at reasonable prices. It's where you're most likely to find a good example of a vintage watch at a fair price. Last, continue to ask questions of us here on OF about your prospective purchases, but understand that we'll want to know what research you have done and what you think before we chime in. That's part of the learning curve that you need to master to become an educated buyer. Wishing you luck in your search and, again, welcome to OF.