It is difficult to determine which frameset you are discussing without more detail. What is thr dropout spacing? Fork crown design (flat or Cinelli Style "Allez")? Feame angles? Lug types? Does it have a headbadge? Etc. Prugnat lugs were teh norm, for the most part.
However, contrary to popular generalizations that "British cycles can be built up with just about anything", which, I guess for the most part is true, Holdworths were an exception.
W.F. Holdsworth Ltd., were importers in the UK for Campagnolo equipment, Fiamme Bars/Stems/Rims, Regina chains and freewheels and D'Allesandro tubulars, and most of their high-end cycles (Professional, Team Professional, Cyclone, ) were equipped with Italian gear, with the usual exception of Weinmann brakes and (sometimes) GB brakes.
The arrangement with the (in)famous Holdsworth-Campagnolo Professional team of late 60's through mid 70's era was that not only were the team cycles outfitted this way, but the fork blades had a chevron decal (transfer) in the red-white-green with the word "Italia" across the top. Kind of an unusual, out of context reference for a British team, wouldn't you say?
(home of boring, televised, prepackaged-and-delivered-to-your-living- room
>From: "KCTOMMY" <KCTOMMY@email.msn.com>
>To: <Cino1947@aol.com>, <Classicrendezvous@bikelist.org>
>Subject: Re: [Classicrendezvous] Which Holdsworth do I have?
>Date: Mon, 2 Oct 2000 23:39:07 -0500
>Holdsworth normally were sold as both built bikes and frames. Most of the
>ones I've seen in the US were bare frames, so there's no "right" component
>group for it. Being English, it would probably have been built with Campy
>from the era, but could have been built French ala the Raleigh Record Ace
>from '73. In the US around Detroit I saw several in the late 70's early
>80's built with high end Japanese stuff, Dura Ace or Cyclone/Superbe.
> I'm guessing that the bike is late 70's early 80's, from the braze ons.
>Early 70's didn't have any brazeons to speak of, while down tube shifter
>bosses that your frame is missing came in around '79-'80.
>Tom Adams, going to bed in Kansas City
>From: Cino1947@aol.com <Cino1947@aol.com>
>To: Classicrendezvous@bikelist.org <Classicrendezvous@bikelist.org>
>Date: Monday, October 02, 2000 8:49 PM
>Subject: [Classicrendezvous] Which Holdsworth do I have?
> >About ten years ago, I found a never -built Holdsworth frame in Roy's
> >Sheepshead Cycle in Brooklyn. It has never been built and I'm wondering
> >is its model name or year of manufacture, and what kind of componentry
> >have come on it.
> >It is Reynolds 531, kind of a turquoise blue, serial #023015 ,with
> >seatstays and no dropout eyelets. Braze-ons include TT cable guides, DT
> >waterbottle, single DT stop for clamp-on shifters, and top of BB cable
> >Is anybody in the group a Holdsworth guru or knows where to find out
> >Josh Berger