The pictures are relly too small for me to see. I may be wrong but it just doesn't look that old to me. I hope someone does prove me wrong and it turns out that you have a good button.
The pic of the back shows that it may be made pot metal/ white metal and the shank doesn't have the look of an old button, it may be a modern blazer button made to look like an older uniform button
Thanks! I googled it and your idea is better than anything I've seen. The bird (eagle or condor) is looking the wrong way but other than that everything looks right.