I just took the cover off a Duncan SJB-3 Quarter Pounder, and it looks almost identical to the pickup in your photos. The sticker on the bottom is different, but my pickup is only a couple of years old. The sticker may have changed over the years.
Mine is a bridge model, with a DCR of 14.0K. On Duncan's site, the bridge SJB-3 is listed at 14.61K. Evidently, the DCR on those pickups varies somewhat; yours at 14.25K is certainly in the ballpark.
I'd say it's likely a Duncan SJB-3.