This thread got me to thinking there was some old-style 450 Ohm feedline here in the antenna-building supplies. A bit of looking revealed my $2 purchase from the Timonium hamfest. Perhaps like the original poster wants to do, I bought it as a curiosity.
But it's not the Belden. It's the cheaper Saxton brand, "low loss open wire catalog no. C-4-100-6". So I guess what I am looking at is less than half of a 100' cheapie cardboard 'spool' of this product. It's 1" spaced every 6 inches, solid conductor copperweld, kinda thin like no. 20 AWG. The spreaders are white and just under 1/4" diameter. The way they melted wires into it reminds me of the polystyrene the old 1/24 scale model cars were made of.
Really wanted the stuff with the clear spreaders.
Maybe that was the Belden.
I'd be afraid to use it for an outdoor feedline. I don't think it would hold up well. Could be pressed into service indoors for that vintage radio decorating touch. Just the thing to prompt the XYL to ask, "O.K...., what's that?".