Wow, I am so sorry to hear that, those were some nice early ones. Please inform us if you get this case resolved, keep us updated. Also, you may have already done the following, but let me lend some advice that might help, just in case you haven't done this yet:
-Of course, inform you local police of the bikes so they can be on the look out.
-Regularly check your area craigslist, offer up, and facebook marketplace, for your bikes (whoever stole them, is likely going to try and flip them to make a quick profit selling them)- the thieves are very possibly from your local area within 20 miles, and might not even realize they are antiques.
-Periodically check any local pawn or bike shops, and have them be on the lookout.
-Check your local flea market, or if there are any sleazy consignment shops around
-As safely as possible, consider driving around some of the rougher neighborhoods in your immediate vicinity, as you could encounter them in someone's garage or around their house, having been recently stolen from you
These are just a few thing I would try in the meanwhile, that could yield results. I wish you the best of luck.
