1976-S Proof Set W/ Toned Cent

I think it adds value to the set for the same reason you bought it. It's an oddity that could cause someone who might not otherwise be interested in the set to purchase it.

However, parted out, I think the cent would have its fans. I couldn't see much from the full set shot, but when I scrolled down to the close up, my thought was "oh, pretty!" If this was my birth year, I'd try to acquire it from you. I've seen some cents toned like this, but since they were all from rolls, nothing in as pristine condition, a few low MS maybe.

You could try to sell the set, but I think you might be able to get more value cracking out the cent, slabbing it, and highlighting that if you were planning on selling.

A great find!

It must be a reflection of some sort because there is nothing visible in-hand in that area.

While I enjoy taking things apart, I have no experience with these cases. Is it relatively easy to free the coins?

That's assuming it would be better to separate them (and I'm leaning toward that). I really don't like the crack in the case (there's another opposite it in the inner housing that's not really visible with my pics) and the "hinged" cover has a nub missing where it attaches so it doesn't open/close properly.

If you decide to do it, break them one corner at a time with a vise-grip screwed down a little too tight. And watch your eyes for flying plastic. That's the way I crack them when I find a color I want to get out. It sure looks ripe right about now.

I'm not sure toning adds any value. I feel toned coins are damaged coins as that is not how they were meant to be. I used to collect nickels but I hated and hated the yellow/golden tones they would get.

I'm pretty much always in the "don't open it" club, simply because almost anything that is collected is worth more as it was issued at a later point in time.

When everyone is cracking these out for one or two coins, it will eventually become more difficult to get the sets as issued.

Of all the proof set lenses, these 1973~1979 sets are, in my opinion, the most difficult. Not impossible, just annoying. The most important advice I can give you is to be patient!