Tell me when you find it, I've been looking of the same stuff for over a year now for my classic 80's bikes! A few old LBS owners I talked to swear they had it in some attic at home or behind the shop.....they never got back with me on it as they promised! Maybe they're deciding to hoard it for themselves instead as they are getting hard to find.
Are you sure it's considered silver? I think the internal "spring" body is silver, but the plastic covering is considered clear.
My LBS had coils and coils of the stuff back in my college days!

Chombi