Alan

All pics are out-of-focus, but doesn't appear to be a furnace.

Nothing rare about those colors. In fact I think they look rather muddied/muddled. Someone overpaid by a large margin.

What appears to be an oily surface is the first thing I noticed.

It has a slight flat spot. On Facebook it would probably be described as: "Mint surfaces with a small "as-made" tool touch mark, as seen under 10x magnification". 😜 This came from the factory site. It was with an Akro machine funnel. I got in in a free box of misc. weird dug items.

From the second photo we can see fine wear across the glass surface without much in the way of impact hits. That suggests that it wore for some time against something abrasive - probably other marbles, or it was lost in the dirt over many freeze-thaw cycles, and then later found.

Opinion: Its only worth $50 if there are two twenty dollar bills under those marbles.

It looks contemporary in those pics - but the color saturation looks way too artificial to represent real glass. What did you do make it so? HDR and a light box?

Nothing wrong with a 5MP camera. A well-focused and lit 5MP pic is far, far better than a fuzzy, out-of-focus pic at 3 times the resolution.

Those pics are almost all out of focus - but it doesn't appear so. Center select your focal point and back your camera away until you are within the lens focal length.

Corning Glass studio made a Thanksgiving dinner made of 100% glass! If you haven't visited the Corning Glass Museum - you are missing a significant experience.

The bottom left doesn't look like wear. It looks like multiple impacts. I'd say "walk away". "Don't sell a marble to yourself".

Is that some plastic film adhering to the Onion - or has it taken a good beating?

Its missing the wispy white that would make it a Popeye. Plus as noted before, its not a corkscrew.

The vast majority is ballast. The handmade pic is out of focus, so I can't estimate condition. All the same - its a common. Anything over $20 is charity.

The sacrifices are significant and pretty much every day. All gave some. Some gave all. Proud to have served and sacrificed.

Modern MK.

The concept of "same run" for machine mades is a red herring. Marble types were intended to match a desired design. In almost all cases that design ran for a very long time (think in terms of a year or years. Rebuilding a pot doesn't mean that a design dies out. Relative consistency was a goal. Retailers ordered what they wanted. There is no reason for two marbles made a year apart to look significantly different, small variances aside.

As you are no doubt noticing - the problem with maglighting is getting the camera to actually focus on the structure of the marble without blowing out the details and causing them to end up blurry.

The first and third pic cases have been backfilled in some of the compartments. My full size Salesman's case looks just like the second pic - which is original. I would be an interested buyer on the small yellow case at the end.

Technically its a "punty" mark.