Between June 1944 and February 1945 Messerschmitt Memmingen issued a series of 15 Erprobungsberichte dealing with ironing out some of the remaining issues with the Bf 109. I have found a couple of these reports on T-2 microfilms and have been helped by the English (as opposed to the Canadian) researcher David Brown with a couple more.
Between us we have found the following Berichte: 2,3, 6, 12 and 15. The quality of course reflects the quality of the microfilms.
As these will be of interest to a number of researchers, I have put these up on WeTransfer for download.
https://we.tl/t-nl8tP5KiVF
This link will only be valid for seven days.
I would be very interested to hear from anyone else who can help fill any gaps in this sequence.