With regards to Maj Puttfarken I have found what purports to be his signature for sale on an internet website. It is for sale under the heading (if my poor German is good enough) "Original signatures of Knights Cross winners with newspaper photographs."
Fair enough, but there appears to be a few anomalies. The picture in question is clearly from a British newspaper (Flying Officer Puttfarken!) and the "P" of Puttfarken has left a blot on the bottom of the picture implying the signature was written
after the picture was attached to its backing paper.
I have attached the picture and signature with a link for your opinion.
http://www.imagebam.com/image/915b8b19210607