kelson, I made up a track tie-down thing from parts from West Marine. They only had one of each in stock, so I had to order more, but at least I have a proof of concept. I used:
Stop-Sail Flat Groove Large 108357 US$9.99
Eye Strap-Flared Top 9/16 149286 US$3.89
Ring-'O' SS 3/16x1-1/4in 534156 US$2.99
So, US$16.87 per track-piece and everything is sturdy stainless steel.
I got a couple of lashing straps for US$3 at Harbor Freight Tools (seller of inexpensive, Chinese-made tools), and now I'm rockin' with the tangy flavor of cheddar. I also got a couple of wheels that I'm going to make landing wheels out of, but that's a topic for another thread.