cheese

Red color should not suggest MFC at all. MFC didn't make red. I would say RW on both of them.

Ravenswood.

Champion seems likely to me.

If you just want marbles for decorating or in a fish tank or something, give what they're worth for that. As far as collector value, I don't think I see anything I would want at all. Even for free. They might have some learning value if you're wanting examples to learn from.

OP is Akro. Last is a Zebra.

Both RW.

It has a flaming pattern to me. I'd call it a flame, someone else wouldn't. It's up to you on this one. Some aren't what we'd call flames, some are very obviously flames, and some like this are in the grey area where the two meet.

CAC slag

X 4

Those are legit bags of Heatons. Hang on to them.

Many many marbles with these coppery blotches are Ravenswoods. I use this as an identification trait. Not a solid foolproof thing, but a trait. Alley and others can have it too. I think it's copper anti-seize product.

It's an Alley. Not quite what I would call a Carnival though. Sometimes when a particular known color combo was made, there was a period of time before or after it when glass was just starting or ending and this could be one of those, or it could be another attempt at the same colors. The Carnival was made at Pennsboro. Many don't know that a similar marble was also made at St. Marys, and it probably just as rare, but not as bright and flashy. It also has translucence to the green and can have mottling. The marble on the right is JABO IMO.

Something funky happened when this one was made. It didn't form in typical fashion. If the colors and all are true on my screen, I think this is CAC.

RW

Correct