An older painting on metal (copper?)

He looks quite a bit like Porfirio Diaz:

But I can't find the precise uniform, either. Perhaps it was made up by the artist, who did not have a real example to look at. Sort of like a saint's portrait?

 

I think it's a good possibility (that or some pseudo-military fraternal whatnot).

So much of it doesn't seem to truly match anything, but it's close enough that you keep thinking, "well let me check one more thing..."