Yeah, if they weren't uncommon the world record wouldn't be a 15 footer killed in west central.

What "they" are you referring to? Clem or the article? cause the article from 1914 that the OP quoted said,

I've never seen any gator that is 1/3 wide as it is long. pretty sure it's a girth measurement.

I believe a 19' gator is very possible. I have been told the same exact story by 2 different older gentle men with places by my camp at millers ferry. One man we will call Barry told me about 20yrs ago when he was building his camp and pier that he shot several alligators illegally of course but he said he was worried about kids and grand kids and some of these were big alligators. Any way he said he got there one evening after work and was having a cold drink and admiring his place when he looked across the slough and seen a big log he didn't remember being there then he realized he was looking at a huge alligator. He kept a 30-30 in his camp so he got it and took a shot at it, but he said it made in the water and disappeared. Any way 2 or 3 days later he and my other neighbor we'll call Bernard were fishing in the slough when they spotted the beast floating in the water. They towed it back to Barrys pier to try and measure it. They said they put a rope on its head and on its tail and it was almost as long as the deck on the end of Barrys pier which is 20'. I was told this same exact story by both men about a year apart without either knowing the other had told me about it. They wound up taking it up in the head of the slough and sinking it with cinder blocks.

I own a 20' Ranger and one popped up beside me on Eufaula that looked as long as my boat. And I wasn't drinking.

If I remember rite they showed a picture of that 19 footer in the gator class in mobile. Said it wasn't confirmed but it was big.