I don't know about the pinto parts, but Stumpy's Traction Bars are quite popular and pretty easy on the wallet. They're not a caltracs style though. His website shows "new design on the way" http://stumpysfabworks.weebly.com/mustang-ii-parts.html may be worth a call if you're interested. I see them come up for sales on mustangii.net once in a while.