The 'extra' strips created for the US Bullpen to fill the insatiable appetite of the British weekly barely made a dent stateside. No longer deemed suitable for the core monthly after the second movie, they were burnt-off in a couple of barely-seen paperback books (good luck finding copies of those at a reasonable price!).
During the period between the second and third flicks, the British title (by now in a monthly holding pattern) started to experiment with British-created strips. Amongst the young creators roped-in was a just-starting-out Alan Moore (who - lets be honest - apparently only had a thinest of grasps of 'Wars lore). M-UK themselves reran a bunch of these strips in their first STAR WARS SUMMER SPECIAL (see here) in 1983 but there never seems to have been any thought of releasing these in the States. That might be because they were barely authorised, if at all, by the powers-that-be at Lucasfilm.
That changed in 1996 when Dark Horse Comics snuck out these two CLASSIC STAR WARS: DEVILWORLDS issues which reprinted (in colour, for the first time, to boot) most (missing one) of the British Star Wars strips. There's nothing on the (new) covers to suggest what's inside or who's on the creative roster.
This year, Dark Horse will finally release an omnibus edition which promises to reprint the entire Marvel UK back-catalogue of Star Wars strips. For most US fans, it'll be the first time they'll see them. Frankly, I find it amazing that its taken them so long to get around to it. Whether it'll include all the original covers created for the British title remains to be seen, but I suspect it's unlikely. It would be lovely if they treated the British Star Wars strips with the same respect IDW are treating the Marvel UK TRANSFORMERS material. Their collections are packed full with copious "making of" material that makes them absolutely essential purchases, even if you own one of the previous reprints (or even the original issues).