Well, well well! Yes, I did miss your reference to Rockauto, sorry.
But, I did not miss your reference to fittings.

I don't doubt that you can make the holes line up in a minute with a rattail file. So that isn't worth discussing.

And, in the spirit of trying to help, seeing that the fittings mismatch was the major problem, I made a suggestion. I suggest you stop looking for what's wrong with me and others and the radiator, and think this through logically.

Take the supplied fittings and put them in your extra parts bin. They are clearly a one-size-fits-all solution to the fit problem. I suppose you could cut your steel lines off and use them, then when you got the other radiator lined up, reuse the originals and connect the cut off originals with short lengths of rubber hose. But I agree, that isn't good enough.

Here's what I saw from the picture: The fittings screwed into the openings in the radiator using what look like 1/4"NPT male ends. So, the fitting to adapt your truck lines to the radiator will have a 1/4" NPT male end.
Now we have to connect the fitting to the transmission cooling lines. I believe the transmission cooling lines end in an inverted flare fitting, like a fuel line or brake line. If my guess is correct, the fittings on the end of your transmission cooler lines are male inverted flare. So the adapter you need has a female inverted flare fitting on the side away from the transmission.

You end up with a fitting that looks like the two that I showed you in my last post. Put some pipe dope on the external threads, turn into the radiator "bung", and tighten. Bring the metal transmission cooler line to the fitting, thread the male part into the connector, and tighten.
Repeat for the other transmission cooler line.

Using the fitting pictured below, the right threaded end threads into the radiator. The oil cooler line fitting threads into the left side of the fitting in the picture.

Problem solved.

Go and do likewise.