What kind of coin? I can't find anywhere

Dear Sirs,

I found this coin on an auction site. Seller wrote that restrike. I don't understand the date.
The marriage was celebrated in 1986. On coin the date is  July 23 1906. Why?
Restrike happened in 1906? At the 1986 wedding ceremony?
So, I don't understand. Can anyone tell me anything about this?
Thanks in advance
Francis

Quote: Archie52Can anyone tell me anything about this?

  I read about this on Numista last year sometime; a member had one also. It was an error at the manufacturer's; it was for a UK Royal Wedding (namely Prince Andrew and Sarah Ferguson, the Duke and Duchess of York) in 1986 but they mistakenly put 1906 on it. I remember that wedding well as I was in the crowd at the front of Buckingham Palace, and saw the kiss    on the balcony.  
 I cannot find the topic now, but here is the error coin (from St. Helena) and the correct one ...



 EDIT: Here is the Numista page, which I see mentions the error also ...
https://en.numista.com/catalogue/pieces19363.html
 So it is not a 1986 restrike of a 1906 wedding, just a 1986 mint error.