You've seen my pics and vids and I've passed 100% in all; I just got back from the restaurant and the waitress called me Ma'am loud and very pronounced, I was shocked and just didn't say anything, but it got me thinking, how do we deal with that, do we correct them or say nothing?

Only if you have a low voice. Then her reaction might be a little entertaining.

Maybe she thought that you were an mtf, and she wanted to be nice?

I wonder if FTM's in the early and middle stages get taken for one of us?

Hmmm, I don't know, good point.

... I'm not sure if this might be helpful, but when I was still in guy-mode I was "ma'am'd" a few times. Not with those words... usually it was "ladies." But I wasn't trying to pass then - for many of the times that happens, I wasn't even on hormones yet. Sometimes people get misgendered - for me, that was getting correctly gendered while in guy-mode. I would like to say that it happens quite a bit, including even those people who you wouldn't expect it to.

And for an honest mistake, the response depends on your character. Some people like to just say it plainly - "I'm a man!" Others might get snarky and say something sarcastic, or rude. Others still would probably just laugh. I would probably bow down in shame.  But ultimately, it's a much smaller deal to the non-victims of a misgendering. Making a scene or deal of it would probably be worse than either a polite correction, a self-contained giggle, or a blank, confused look.

If I don't bow my head in shame, I go for the blank, confused look.