Just as title states..being told it fits a 65 or 66 mustang..its an interesting piece but the seller does not know who makes it.
I removed the same looking bar and mounting from my '66 GT. Mine didn't have any links and the plate that installed for the links looked different from yours. Don't know the mfg'er but I didn't like the fact that the frame had holes drilled through it to mount the channel looking thing that the bar mounts on. So, to at least answer some of your question, I'd say yes to whether or not it'll fit a '65/66. Greg Z