No worries on grabbing the pics; sorry they were not the best.
They fit extremely well (Sanderson suggests mounting "bare", without any gaskets). I saw the square tube in the pic as well (had not realized it before) and cannot remember if the ports were square or not. These are specific to my engine (Buick v6) so I would suspect that they would be specific to your engine as well (I can't remember exactly what you have, and I am sure you already have the site, but here it is anyway!
https://www.sandersonheaders.com/). As you can see in the pics I have these mounted with Allen head bolts and I have no leaks
Enjoying watching your build; happy to provide any additional pics that might help!