I just acquired a panzer M-43 with dull, silver buttons. They are not pebbled, but the 4 hole "dished" variety, as seen on plastic buttons and those made of other materials. They are metal, non-magnetic and have a nice silver-gray patina. The threads are not crisscrossed through the button holes, but run parallel to one another. I don't doubt the buttons are old and appear to have been on the cap for some time. Is this button material and configuration known to be of the period? Thanks.