Harriers I posted a short while ago, I believe that the sprues themselves were procured by Battlefront from a third-party manufacturer, Ace Corporation. However, while the plastic injection sprue includes drop tanks, rocket pods, and bombs, the Battlefront box also contains a sprue of resin KH-25 (NATO: "Karen") air-to-ground missiles.
All in all a pretty nice box set and should come in handy in games of Team Yankee. Can't argue with the price point either - $39 CAD compared to over $60 CAD for the old resin box set. The only downside of the injection kits is a slightly more fiddly way to mount them to the flying stands - but I'll take that tradeoff for $20 per box. Plus most of the weapons are injection molded and perfect - no worries about the crappy resin ordnance that plagued Greg in his build.
Onward to the West!