Found them on EBAY The key was knowing what to search for!
Thanks much !!
The only ones I found on the Bay are in the UK, but they are not expensive (~ $12 for 100 feet w/100 screw eyes). Am waiting to find out the cost of shipping -- could be more than the product itself, depending on the weight
Also found a lot from Ikea, (Deka) but they look like the springs are in the brackets, not in the wire. There may not be springs at all, since the instructions show that you tighten the wire by turning the brackets, sort of like a turnbuckle. It also appears that they need to be mounted between 2 walls, unless you add an L-shaped bracket to their brackets.
Found a lot of wholesale ones on Google as well, but no retail in the US. Could be an opportunity for someone to import them from China...?