Charro Cinco De Mayo Embroidered Mexican Mariachi Set 2-5yr Old

Charro Cinco De Mayo Embroidered Mexican Mariachi Set 2-5yr Old No tags. Appears to be made of a wool blend material and very well made. The pants confuse me as there are buttons, but no loops, holes etc to tie them or close them. So, I don’t know if I’m missing sometbing on how to do this or if they’re missing a piece. Please see photos. I found a couple of these and they all seem to be the same and meant for a 2-5 year old size wise.