I had a set of those a couple years ago, and was plenty pleased with them. I didn't take the measurements you're asking about, but yes, the flanges were plenty thick, plenty flat and sealed just fine. Actually, I was quite impressed with the quality of them, especially given the cost. I used them on a run stand, then temporarily on a boat while some were being built, and then sold them for just about what I paid for them. He was nearly happy as I was.
I can't tell you specifically which ones I got (I think I paid 108 w/shipping), but if they are all alike and they look like they are, I would not let the price stop you if a pair of block huggers is what you need.