I have 2012 unlimited Arctic with the bracket shown below.
I bought a newer soft top on Craigslist which is shown with the spring assist in the picture.
I don't know what mounting bracket will make the top fit.
I'm at a loss for the part #
The bracket shows is for an older wrangler without the spring actuation unit. Your bracket needs to be the flat rectangle design shown here:
The flat edge on the left is what is mounted to the spring actuation. Then the curved position attached tot he roll bars which could be hidden under the padding.
So In other words, You've selected the correct bracket, but incorrect soft top. the soft top hardware/frame you got is off Craigslist is a 2014-2018 (newer Wrangler) and isn't compatible with your older 2012 wrangler.
Note to all readers:
Please ask questions about products before you buy off sites like Craigslist, eBay or Facebook marketplace.