Sharper pics would help, but even without, I'm going to say counterfeit.
What I'm seeing: most of the devices are mushy. The bust is quite mushy with a lack of sharpness, but LIBERTY is still sharp? Red flag. Why? Because LIBERTY was in lower relief and not as sharp as your example shows. Also, the argument of a later die state can be countered by the fact that there are no metal flow lines. Fields are smooth, there are no signs of clashing or polishing, no signs of metal flow from aging dies that match the lack of sharpness of the chiefs bust.
Lettering of the date also looks off/inconsistent, as does the designer initial. It's normal to see some mushiness in the designer initial as dies wear, but again, there is no sign of metal flow in that area.
Same goes for the MM, surprisingly sharp with no signs of metal flow surrounding it.
Also, the back of the Buffalo directly below EPU "appears" to be deteriorated from die use, but yet EPU is still almost making contact? Typically with
Die Deterioration and die use comes die polishing. Die polishing removes the lowest posts of relief in that area, causing the devices to become "smaller" and the fields affectively "larger". With die polishing EPU typically thins out, the back becomes sloped, which in extreme situations gives us the "broken back" varieties. This separation can be seen and is a good marker for authentication on the 37-D 3 leg.
This is not seen on this example, and again, the lack of true
Die Deterioration, die polishing, metal flow, etc is a red flag and has me pretty firmly at counterfeit.
All they said, thank you for sharing, it's quite a cool example!
Note: didn't proof read any of the above, sorry for any grammatical errors.