I think I'm getting a lot warmer. A Classic Rendevouz member thinks it is a early 70s W. F. Holdsworth "Putney shop build, not factory*" and pointed me to this picture which matches most details exactly:



The only major differences are that it has a riveted headbadge (mine has no holes) and its owner found a stamped serial number. Edit: Just noticed this one has no mount points on dropouts, another difference.

*Not sure what this means exactly yet. But I'm learning about British bikes pretty fast now.

(and [MENTION=333224]juvela[/MENTION] I wish I had a Bates with those crazy forks! Apparently E. G. Bates split from that Bates to build his own bikes, so they are two different companies. But the same Bates.)