I figured out who all the Knock-Offs are KO's of thanks to two very helpful guys: tigertracks 24 & JelZe GoldRabbit.

TRANSFORMER BASE UNDER CONSTRUCTION:
My brother and I took the 2nd largest doll house and converted it for use as a home-base. My brother's been in the Mexican military (actually the Pentathlon) so he painted it in a military style, which my son will undoubtedly love.

Here it is, exterior:

and interior:


We got the doll house at the Salvation Army for $5. We have a larger one than that that's still a doll house, and a smaller one, which also gets used as an opposing Transformer base alone with nearby furniture from time to time.

OPTIMUS PRIME COMES TO A NEW GENERATION:
Optimus Prime was my favorite Transformer; bar none. Soundwave & Grimlock came next, but Prime was my guy. I used him so much his arms wore out so I had him command from Teletran 1 on my play shelf. So when I realized that my 10yo daughter, of all people, really, really liked Prime, I gave the figure I'd stashed away for me to her, and seeing her reaction was bittersweet...

My 10yo daughter, Maria de Guadalupe, didn't know that I had bought the figure; she offered three times to buy me one thinking I didn't have it (she said she was once, and then kept reminding me that she was as soon as we went to the store), and then enumerated to me why she thought (based on seeing the original 1st Generation 1984 cartoon) Optimus Prime was her favorite:

"He's a good leader, he's not so full of ego like Megatron that he gets things wrong all the time. He's always concerned about the other Autobots. He's brave."

Her words, near as I can recall them; I revealed to her that I had already acquired Optimus Prime and had him in hiding, and instead of giving him to me (my original plan), I gave him to her.

He's what I used to make my new avatar.

Oh, and here are the kids playing on a weekday using the doll house prior to it's repainting:


Even my 10yo girl enjoys this:

which is obvious because now she owns Prime, and, as she said just now, "I... think... he's so COOL!"