Alan

Here is one of Bill's with dichroic sunglasses:

Very good call - Harry & Wendy Besett. Its large - 3" dia., 6-stage. IIRC it took a bit over a week to make.

That space has always been a routine fact of construction. There isn't anything unusual about it. The naming convention that you mentioned someone is using is quite new (I've been collecting handmades for over 3 decades and have never heard anyone use it) and seemingly an artificial and unnecessary invention. I can only guess that person is using such inventions as a means of influencer branding.

Close up which "gaps"?

Yes - MK. These are more recent. They usually have excess colorant precipitated out - sometimes chunky.

Yes. Approx. one zillion of these were dug.

Machine made. The construction is machine made, absent the pock mark. No sign of cane construction.

I don't see a signature. Without one, the technique could be attributed to quite a number of artists that learned the vortex technique and the outer decoration. I once watched over a dozen artists doing vortexes at the same time at Wheaton. That was just a very tiny sampling.

Modern.

It appears to be a less-colorful egg yolk oxblood. Is there a reason you disregarded my question?

Flopover single ingot.

What is "strange" about it?

It lacks enough of Master glass flow at the surface for me to say Master. Its dark glass. I'll venture only so far to say "not U.S."

Variation is normal. I suggest that you move away from a "variant" concept = more cash. It causes people to misidentify and invent new names and ideas chasing money. Light is not white. Different lights emphasize certain colors. The sun brings a broader spectrum of color. I can make a marble look different just by changing lighting, angles.

First pic is fine. On the rest - the camera is searching for what you want it to focus upon. Touch the marble on the screen to manually lock the focus, making sure that it is in focus before taking the pic.

+1 Try not to think of glass variations as some new/different type. Marble making wasn't a precision manufacturing process.

You must be making that extremely early.

Pelt

Nice!

Akro didn't do "runs". They ran machines for extensive periods until the pot slowly dissolved and the firebrick ended up in the glass, signaling that it was time for the pot/crucible to be rebuilt. That rebuilding was a big effort and meant that it was down for weeks. Vintage marble making made marbles for small fractions of 1 cent. They fulfilled very large orders. They did not do short "runs" This concept is an invention. This is a recent invention. If someone disagrees - please ask them to provide Akro documentation that validates this new claim. I'll be interested to read it. Otherwise, its just an invention to create the allure of rarity and hike the asking prices. Folks shouldn't be taken in by these stories. "Every questionable marble sale needs a good story to support it. A good marble needs no story at all".

Odd colors. I see the hint of Master glass flow, but I'll defer on an ID attempt. Perhaps somewhat brighter lighting may help.

This is a form of junk science spewed by a Google AI bot, then seized upon by an inexperienced person who only has that to lean on. I suggest you defer trying to invent new specialized naming to a marble in front of people with decades of hands-on experience that tried to guide and advise you - and you continue to ignore. It's the same glass/marble that I and several other people here have owned, handled and known for decades. It may be new to you, but it isn't new to the rest of us.