I want to acknowledge the hard work and efforts of GAD to pull together and publish information on the Guild HB-1 pickups and their successors.
Late last year, I started thinking about getting another Guild electric archtop. There wasn't anything for sale locally so I spent a lot of time looking at guitars for sale on Reverb, Gbase, eBay and Craigslist. The guitars of interest were the X-160 (not rockabilly), X-170, X-150D, and X-180 built from the late 80s through the early 2000s. I also found a lot of info on LTG about those guitars and others that weren't really what I was after but I enjoyed learning about them all. Sorting out and summarizing all that could be an whole article on it's own. What is of interest here is pickups.
I kept what I'd learned from GAD's article and from other LTG posts in mind as I looked over scores of ads for Guild archtops and semihollows. For guitars advertised as 1995 or newer I'd carefully examine the pictures of the pickup adjustment screw spacing. My casual observation was the narrower screw spacing indicative of Fender made pickups started to show up on some guitars advertised as 1998 models. There were also some advertised as 2000 models with wider screw spacing indicative of HB-1 or the Seymour Duncan version. Essentially it appeared to be a mixed bag between 1998 and 2000. In some cases it wasn't possible to verify the model date because a serial# wasn't shown. GADs recent update shows that a Fender made pickup can have an adaptor plate to use a pickup surround with wider screw spacing. That may be a one off or maybe there are more out there like that. Who knows?
It seems unlikely that Guild suddenly ran out of HB-1 pickups the day Fender took ownership in 1995. The pickups made by Seymour Duncan from stockpiled HB-1 baseplates and covers were reportedly produced for about a year but the supply a of completed pickups may have outlasted the actual production. It's just conjecture on my part but it may be that Fender made pickup didn't appear on Guild Electrics until 1998 or so and then only on specific models while the the older supply of of SD pickup was depleted on other models.
Thanks again to GAD and everyone else who has written about the guitars and pickups on LTG.