I remember the grab boxes, I still have the 45 BB RC that I bought from one of them in must have been 1982. Never had any trouble with it (Duke made me promise to always use 20% pure castor in it, and I always did, although to be honest, I haven't run it in 7 or 8 years, but it ran fine the last time I tried it). BTW, not saying they DON'T still make engines, nor that they're planning on quitting doing so, but you know it's just a small part of their business. They do a lot of (and I suspect make the majority of their income from) contracting sub-assemblies and 'to order' machine work for other manufacturers. Here's their website for that line of business:
www.foxqualityaero.com