A vintage Astrochron, or variant, floats my boat.

The vintage Astrochron is to die for, especially if it's in good original condition as yours seems to be. I can't see the pusher spacing, but if it's got the Valjoux 72 column wheel movement it will be uber collectible with a price to match.

The 'Classics' page on the OWZ website has examples of Vietnam era O&W watches. The ETA2824-2 M-series are much later, dating from around the year 2000, and are very collectable. My favourite is the M6.

The watches were originally mail order and never came with boxes; the plastic case is aftermarket. The build date range you got from OWZ suggests that it was probably supplied by one of Albert Wajs' distributors such as WestCoasTime (US) or Kult Uhr (Germany). Unfortunately WCT are no longer trading and the proprietor of KultUhr has no remaining stock - I purchased what he had left!

I thoroughly recommend the new Falcon with 5-jewel Ronda movement. With it's round pushers, brushed case and superb Super-LumiNova lume it's closer to the spirit of the original quartz BAF than its Tritium predecessor. They're a bit expensive but more realistically priced ones in near mint condition occasionally come up on eBay, so worth a look perhaps.

My guess is that they were made in the very late 1990's or early 2000's. It doesn't appear in any catalogues as the catalogues that do exist covered the earlier vintage watches. I think Joseph Ollech died in 2000, after which Albert Wajs released a whole raft of different designs in relatively small numbers, including this one, but I've never seen any catalogues/leaflets for later watches aside from that produced for the Aviation/Navitimer. There are passionate collectors out there (like me) for whom there's nothing better than an original O&W; my particular interest is the M-series and '60s chronographs (image). Yours seems to be a nice example and it's great that you've had it serviced. The pheon / Broad Arrow was decorative; no O&W watch was ever intended for military issue. As for value... I sold mine to an enthusiast for just over £400but I don't know what they originally sold for.

These are very nice watches; I think they have the automatic ETA 2824-2 movement. Would certainly look the business on a CWC NATO!