This Davidson has a similar bottom bracket drilling:
http://www.wooljersey.com/gallery/v/...05451.JPG.html
Apart from that, though, the fork crown, fork legs, the lug cutouts and some other details all look like things I've seen on one or two McBain bikes out of Tasmania, Australia. They still operate as a shop so it might be worth sending them an email to see if they've kept a registry:
http://www.mcbains.com.au/index.php?q=node/213