The LM1496 from National Semi (I think it was available at least by 1976, possibly earlier) was listed in the National databooks as a direct replacement for the MC1496 (which came out in 1972, I think.)
See Bitsaver's copy of this 1989 databook from National, for example:
If you check the MC1496 datasheet and the LM1496 datasheet then you will see the following:
The only apparent difference is that the MC1496 shows a diode (lower left corner) where the LM1496 more correctly shows a diode-connected BJT. But they are the same thing.
You can substitute one for the other.
The fact that you find the documentation of one of them to say some different things than the other is, I'm sure, more about the goals of marketing at the time. There is so much written on the MC1496 (including AN531/D) because, at the time circa 1972, they wanted to get out all the possible uses and provide both breadth and depth so that designers could use their imaginations more readily. I suspect that by the time National Semi got out their version (a little later) the marketing needs (for National anyway) had sharpened up a bit and so their datasheet likely reflects that. But this is just my guess.
Regardless, one can replace the other.
P.S.: Just from my personal perspective, this is perhaps one of the finer contributions by Barrie Gilbert.