Odd you should think of Bob Jackson as more nearly "bespoke" than Holdsworth. In much of America, the image would be quite the opposite. The the 70's Jacksons were sold in America in large numbers, and though many were sold as framesets, these frames were rarely actually bespoke, although it was certainly possible to place a custom order. Holdsworth had a bit more mystique for the average American cyclist, simply because were saw far fewer of them. I don't know the actual number built of either marque, although in the 70's I'd think Jackson production might have approached that of Holdsworth.
I guess it's a matter of "familiarity breeds comtempt". I have much the same view of Colnago, because in the late 70's there were very many Colnago's sold in America, probably built by subcontractors. They had appropriate geometry for the criteriums that then constituted most of US racing, but the finish and detailing was nothing special. Many viewed them a mere tools appropriate to bash around in crash-filled criteriums where one would not want to risk a Cinelli Supercorsa or the like. I still tend to think of Colnago that way. I did finally buy my first "Colnago" this year, but it is an ALAN-built DUALL, which is rather a different animal.
Big Spring, Texas, USA
> From: firstname.lastname@example.org <email@example.com>
\r?\n> Subject: [CR]Holdsworth / Bob Jackson et al... (Ian Briggs)
\r?\n> To: firstname.lastname@example.org
\r?\n> Date: Sunday, December 28, 2008, 1:48 AM
\r?\n> Asking price aside - just a subjective personal observation
\r?\n> on this interesting discussion...
\r?\n> It would be nice to know for sure the provenence of the
\r?\n> frame in question of course but (quote) "If you believe
\r?\n> her to be a Holdsworth, it is a smacking good deal; if you
\r?\n> believe her to be a Bob Jackson, it is still a very smart
\r?\n> Well, I was an amateur?road man (massed start) ion the UK
\r?\n> during the era that this frame was apparently built, and for
\r?\n> the record it looks identical - even down to the fastback
\r?\n> arrangement; to a "Ken Ryall" I bought in the
\r?\n> early '70s and which was almost certainly sourced from
\r?\n> At that time Holdsworths were held in reasonably high
\r?\n> regard by the 'peloton', mainly due to the
\r?\n> professional team that was dominant in the UK then.
\r?\n> However, Bob Jackson, Ellis Briggs, Woodrup, Dave Russell,
\r?\n> Mercian, Pat Hanlon etc., etc., basically anything
\r?\n> that?could be regarded as bespoke (rightly or wrongly) was
\r?\n> far more desirable to us... There was, I believe, a
\r?\n> perception / bias?that any Holdsworth really wasn't
\r?\n> bespoke because of the large number of low-mid range frames
\r?\n> they also produced. This is a bias that I retain to this day
\r?\n> I'm afraid!
\r?\n> So, long story short - if this frame finally was proven to
\r?\n> be a Jackson - it would be hugely more attractive to me
\r?\n> personally, and thus I'd be prepared to pay a higher
\r?\n> price (if I were in the market).
\r?\n> Ian Briggs
\r?\n> Luton, Bedfordshire, UK.