I was wondering if you could find some information on the 1999 Upper Deck Mark McGwire 500 Home Run set. There is a silver and a gold version available for all 30 cards. I was wondering how many of each set were produced and if the gold version could be added to the OPG? Below is an example of the silver and gold card.<br />
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Silver<br />
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Gold<br />
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Silver<br />
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Gold<br />
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