Experienced Dolly grip advice needed about track

[hscully]

I have an opportunity to buy two lengths of used Matthews Dolly Track. Matthews makes two types, heavy wall and stainless and they cannot be used together according to documentation. Is there any definitive way to tell them apart? For instance one of the lengths has red clips the other black (maybe dark green). Plus the guy says "one says stainless."

I can post pictures if that helps. They're older. The cross members are not black.

 

[hscully]

Got' em... thanks for looking. The guy who sold them to me is a pro DP so he knew about the differences and they match beautifully, smooth as silk, nary a bump! Now... how to get them around...