Boulders initially came into the UK through sShockwave in nottingham. Thats were my 1990 ish Gazelle came in through (six speed and Rockshox RS1 to match). But they didn't sell many.
Later distribution was through CVI, whi also dealt with risse shocks and latterly they took all the answer spres in the UK from ATB sales.
Yes, the bushes are oilite, turned from bar, and yes, a ground steel shaft. Very easy to machine replacements. When the time comes, give me a shout and I'm sure I can do somehting. You'll have seen my starship Lt. It didn't need bushes as the frame was NOS, but at least there is something to measure. 4 bushes in all IIRC.
Last contact with Mr boulder was about a 2 years ago, but it bounced when I asked about a soft spring for my girlfriends defiant a year ago. Rich mentioned that Boulder wasn't dead, they just build frames mainly locally for existing clients. I'd like a paris roubaix road frame. And I recently missed out on an intrepid in Vegas-- I was just too far out of cash. .