Thanks for the help, everyone. Much appreciated.
Also, thanks p-dub. One of our locals also corrected me on our lhs forum.
We have since found a source that is selling them around $4 - $6 each new (Hiller disk blades
). I have also asked them to look around their area for farms to try to source some that have outlived their usefulness on the farms.
I have seen these used at a lot of major races and am not afraid of them damaging the carpet. I do have an angle grinder that I can use to prep the edges to make sure that they will not damage our carpet. I don't think that they will move around much, as they weigh in at aprox 3.5 lbs., but then there is always the velcro trick.