What polish and laquer for bare metal?

I use silicon gun oil on my raw frame... as long as I give it a good coat every week or so it stays rust free with no visible change to the frame. Have to get all over it though... I missed one side of the forks one week and had to re-sand it....

And I'd be interested to know how the 'after' might look, and whether boiled linseed oil is good as a long-term weather-proofing solution.

Depends on whether you get the orange boiled stuff from B&Q, or the light edible stuff from a health food shop. The orange stuff will make your frame look darker and slightly yellowy (especially with several coats). It's not an unpleasant look, but it is noticeable.

I have moved on to the edible food supplement (a.k.a. flax-seed oil) which is barely noticeable (it is used for mixing oil paints, after all), except that it dries to a satin finish. It takes longer to dry than the orange stuff.

The orange stuff is properly weatherproof - I used it all winter without re-applying, and didn't have any rust when I stripped it all off in the spring. I only hosed the bike down every week or couple of days, too - it doesn't wash or flake off, except where you repeatedly handle the bike (mine had a bare patch by the downtube shifter) but it's easy to reapply. The edible stuff... I don't know, I haven't used it over the winter.

How's the frame a year on? Did you use linseed oil in the end?

Rusty as can be, awaiting a respray.