I remember those buckles from my collecting days, there was a lot of speculation as to whether they were official party issue or not. With them not being makers marked I always though they were not official party pieces (the Nazis put stamps and marks on literally EVERYTHING big enough to be stamped), and I believe it has been determined they were likely souvenir pieces sold at party rallies. Of course I can't find more than two collectors who agree on an origin for them and thoughts range from a pre-war "good luck" buckle to Finnish military and even early Boy Scouts...