Silver Proof minting error

[DrLarry]

I have had a few of these 2009 Family silver sets this one is #1295 of 1500 I am sure all the real coin collectors will find this a little boring and I only ask your advice because I have donated it to the charity and would like some idea of the rarity as a failure in the Royal mint not to have noticed 6 large pieces of silver on each of the edges. The metal twists down the side so much so that the coin will not ever sit in the capsule.  It is sitting high and one slice of the silver is cutting into the plastic on the underside. 

the weight for the silver proof is correct and all aspects of the coin are as they should be for the silver proofs except this.  It must be very unusual to have struck it wrong, examined it , quality controlled it, then carefully placed it in the capsule where is doesn't even sit flush. 

[Mr T]

Unusual indeed for it to have passed quality control. Hard to say what it is but maybe some sort of lamination fault?

I get the impression that circulating errors end up being worth more than mint set errors.

[DrLarry]

yes I think they do however if I see them going cheap in various places around the world who follow the guide price in SPINK for the sets they can sell for a lot more over here so it makes some profit for the charity.  I can usually make a couple of hundred profit for them that way. I think any proof error getting through is a rare thing though, the fact that this is such a profound failure on each of the angles even more so.  I would think there may have been a jump and restamp error which has caught the edges some of the metal is folded down along the edges but one piece sits very high.