It is a shame that there isn't a online museum of knives. Some place you could go and get the facts. The archives of this forum are a defacto museum. Old school, he doesn't maintain a website that I know of.
You have good taste picking the Spike to collect.
Steel Addiction has a photo of the anniversary model of the Spike with BG-42blade steel.
The auto version of the Spike, model 1,000, used G-2 for its blade.
In my experience ATS-34 was the only steel used in the production models of the 640 & 650.
I saw Phil Boguszewski at Blade in Portland, OR last year. A dealer from Washington State had a few of his pieces for sale, nothing less than $1k if I remember correctly. Knifeart has a photo of the man himself.
You could give him a buzz. His number is in the book, Lakewood, Washington. And, he is scheduled to be in Solvang in a few days. His work shows up irregularly at the g/k shows in this neck of the woods.
Best,
oregon