Can you help to identify these frames, bikes or parts?

http://www.classiclightweights.co.uk/builders/holdsworth.html

I'm after some more info on a frame before I decide whether or not to hawk it on eBay or keep it.

It's stamped on the bottom of the frame and the forks: 66382

Holdsworth?

But made from some italian steel I've never heard of - Tubi Oria 9506

Plain lugs on the frame:

And on the fork:

It came with a Tange Headset and a Cinelli stem and bars. Thanks for help.