My kids just picked these covers for me in a group of 20 or so from Memel & Danzig at an Estate Sale for a few dollars.
A few nice finds, especially in the first image.
I believe the blue and buff stamp with red Type I overprint is Memel Scott #32 on cover with a CV of $72. or is it #41 with Type II overprint font?
Along with #69, #77 (bottom left, green), #72 (horizontal).
On the 3rd image, I cannot make out the overprint on the "sower" small stamp in the center. It looks like 2 or 20 Marks on a 20c stamp, but I cannot find that combination in the Scott Catalog. Any suggestions ?
and the last image with Danzig, looks like ##68 on cover CV$13