DJ, in the Shepard Paine book, Modeling Tanks and Military Vehicles, there is a very good diagram on how to make the tie-downs out of both metal and out of sprue or styrene rod. I can scan and send you the page if it will help, a picture is worth a thousand words. I would also recommend this book to any military modeler, in fact, it was my first modeling book. Just to show you how long this book's been out & good this book is, the cover price of mine says $8.95 and the MSRP is $14.95, Squadron carries them for $13. First printing was 1982.
I came across this book today in my local hobby shop. It's really good. The first one I've seen that actually shows and explains how to do some detailing projects and how to build things with sprue. The cost was $14.95...guess I'll need to put it on the birthday list.