1911 Iran 491A Not In Scott?

I've been accumulating Iranian stamps recently (seems worthwhile to do so) and while building the 1911 perf 11.5x11 varieties I noticed 493a is missing from my Scott Specialized. Is it just a misprint?

Do you mean 491a? 493 is 26c. 491 is 1k.

The 24c and 26c are between 1k and 2k.

There is a 491a but not a 493a.

You are absolutely right, Nicholas! Thanks for that. The 1k is 491 and I should have stated that better. I will edit the title.

Is the 491a in your specialized? It doesn't show up in the one I'm using:

490a. 13c.
492a. 24c
494a. 2k
495a. 3k
497a. 5k
and so on...

The 491a, 493a, & 496a are absent, but it is a decade old so I probably need to buy the newest one.

Does the 496a show up in yours as well? It's quite rare without the variety, so probably not. Also, what's the value of the 491a you see? It must have been discovered recently, or the version I'm using just had a misprint.

I have a 2019 classic.

These are the 11.5 x 11 tall portrait:

My 2017 standard catalog DOES NOT list the 491a.

2025 Classic Specialized has the same catalogue numbers as pictured by NicholasC, with some small changes in CVs (except the used 498a, which jumped to $45.00).

Thank you both! I'm very happy to hear about the 10k increasing so much, but I wonder why it was singled out. And why in the world did a used 492a drop from 15 to 0.50 in just a few years?? I can't understand why or how such determinations are made.