Phil, somewhere I have a photo of Don (shooting at the old Souhern California range) with one of his stocks. As he said, weight was about a pound. The fabrication didn't look difficult; depends on how much was epoxied, how much bolted together.
Difficult part from my end would be to find the metric tubing so I didn't have to sand stuff to keep it under 3 inches wide.
There were those who felt it ugly -- Honest to God, when I expressed interest, I got a phone call from Don Neilson begging me not to make one, just too ugly . . . (well, he was also trying to sell me a barrel block . . .)
If I do any more experiemnting, I think it will be with a "stock" built around a small, 3-inch barrel block and a skeleton butt. Forearm to be off a tensioning tube. But it's over 50-50 that my experimenting days are done. I could just tell Terry Leonard what I want -- a barrel block that will accept more than one action -- and he'd build it out of his composite woods. Pay and wait gets more and more attractive as the years pass.