That numbering system started in 1973, so it would have to be 1980. Here's a scan of the original notice to dealers Http://www.mindspring.com/~sblackstone/sn.jpg
As you can see, it applies to quite a few factories as well, not just worksop, and not just 531 and 753 frames like retro Raleighs says. (Did Worksop make any 753 frames?)
Wayne - being in NZ do you ever see a Raleigh lightweight with the "M" code for the Malaysia factory? Or did that one only make stuff like 3 speeds?
Steve Birmingham Lowell, Massachusetts USA
Message: 1 Date: Mon, 23 Feb 2009 12:09:52 +1300 From: Wayne Davidson <wayne.collect@xtra.co.nz> Subject: [CR] dating my team Raleigh track bike frame To: CR <classicrendezvous@bikelist.org> Message-ID: <49A1DB40.1020307@xtra.co.nz> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed
Hi all, after trolling the net, is it safe to say that my serial number, WM0006677 4 means that its made in Worksop in september of 1976 and is #677?, the 4 I've not been able to ID that, if you want a pic I'll take one............regards wayne davidson Invers NZ...........