Ultraman kaiju minis from Mexico

I recently acquired this really fun set of vibrantly-colored kaiju minis, and it's still a bit of a mystery to me. Here's what I DO know about them:

• They're from Mexico
• They're all kaiju from Ultraman. I am not a kaiju expert and sometimes have trouble telling some of them apart, but from what I was able to tell while doing research, the characters are as follows:  TOP ROW, left to right: Red King, Gomora, Bemular, BOTTOM ROW, left to right: Gomess, Alien Baltan, Gudon. Can any of you kaiju experts out there confirm whether I got that right?
• Their tails (and Baltan's arms) are removable, so you can pop them off and plug them back in. 
• These six make up a full set (90% sure as I've never seen photos of any others anywhere).
• They're about 1.75 inches tall on average.
• For some reason, some of them are made out of hard plastic while others are made from soft rubber. With the rubbery ones, it's a bit hard to plug the tails in so they stay in place.

Here's what I don't know about them yet and would like to find out:

• What year did they come out?
• Was the set released under any particular name?
• How were they sold? My best guess is snack food premiums, but that's only a guess.
• Are they bootlegs of Japanese figures or original sculpts?
• How many different colors were made? You can see additional colors of the same sculpts in this image from Flickr user Monochromatics Figures.

Do any of you guys have any of these, or can you help answer any of these questions or shed more light on their origins?

Kaiju attack! (Ultraman monster keshi)

Can you ever have too many kaiju? The answer to that question is obvious. Just look at the awesome assortment of Ultraman monsters pictured above, which all come from a 1990 Japanese keshi boxed set called "Great Monster the 30" (yes, it's actually called that). These guys all came together in a M.U.S.C.L.E-styled long, flat cardboard box along with a red Ultraman figure, a tiny dice and some sort of paper game board. You can check out a photo of the package along with close-ups of some of the monsters in this previous post.

Ultraman: 'Great Monster the 30'

What: A Japanese multi-pack of mini "kaiju," or monsters, from the Ultraman series. The pack includes 29 different light flesh-colored monsters and one red Ultraman figure, all made out of soft plastic. As if all of the monsters weren't cool enough, you've got to love the bad English of "Great Monster the 30." Really nice set!

When: 1990

Where: Japan

Who: Bandai