The vintage ones sell well in lots on eBay. I can't tell the age of these from here. Nice find for 5.00 regardless. Look closely at the catches and the owls and compare them to vintage ones online. Owls are very hot right now and there are some excellent repros around - which also sell, but not as high.
When it comes to costume jewelry, generally speaking, signatures are a must. However, yours do look vintage and people do like owls so, you should do okay with them. Check the chains, sometimes a 925 chain will end up with a costume pendant or vice versa.