this is the 1947 restrike... the coin test right for gold and weighs right... but it looks like it has a matte finish..

any thoughts besides just someone sandblasting this coin?

No, but it sure looks nice Matt!

I saw a very similar one on Ebay today, NGC graded it MS-69. There is nothing that looks off on this particular piece, but it seems like the rim is soft below Libertad.

in hand the coin looks like brass but test and weighs right... it has no luster what-so-ever... i have seen a lot of these coins... and this is the first one i have seen like this.

Do you wonder that someone polished it with something like one of those silver cloths? If that was indeed what someone did to it, they did a good job. Without travelling down to Indy and seeing the coin in hand it is kind of tough to determine. I sure regret that whilst the Mexico City mint cranks out these 12 oz monsters for stuff like the US Constitution etc, and rather unattractive Onza coins, that they never ramped this design up into one of the 12 oz coins. I just love the design, but the fact that it has a Latin hottay on it makes it all the better.

Feathers under the right arm look very weak too
It has the full look of goldplated
Maybe someone finally figured out how to strike wolfram and goldplate it
Then all sizes and surface testing would be perfect and you would need to saw the coin in half or seriously cut it to find out

Doesn't look right. I have only one 50 peso coin coin and it's pretty scarred up, like it was a pocket piece for a while. Here is a picture of the coin, though this pictured coin is heavily worn you will note a lot more definition in the coin. Also 50 peso coins being 90% gold and 10% copper tend to show to the red side like Krugerrands not buttery yellow like .999 coins.

It does look weird to me too.