I think, don't quote me, but there are 2 main styles of "Klassics".
There are the Keystone Kustomag Klassics, and the Keystone Klassics (now made by Cragar).
The early Kustomags I've seen with both black and standard cast finish centers, whereas the ones made by Cragar (current ones) are all black.
Here's a guide:
1. Early ones are all standard bolt circles- no uni-lugs.
2. The casting on the outer edge of the spokes are different between the two. Early ones are squared-off almost to a 90* angle, whereas the new ones swoop out to meet the hoop part of the wheel.
3. The center part (where the bolt circle is) of the early style ones is perfectly round, whereas the new ones swoop out to meet the spokes (more webbed look).
The old-style ones go for big money, whereas the new-style ones, not as much. I believe you have the newer-style ones.
Hope that helps.
Sorry to disappoint
As for value, you can buy them new from Summit for ~$170 to $200 depending on size.
As for the centercaps, that's another ball game. I've seen a lot of different styles. I think it's safe to assume the casted "Cragar S/S" look-alikes with the big "K" and small "Keystone" underneath it are the most correct for the early versions. The slanted ones both cast, and sticker-type ones are for the later versions.
EDIT: I'm digging into the valve stem location part of this, so there may be 3 types.