Yes, I think the serial number is altered.
I see faint lines running horizontal with the numbers (arrows in red) and the makers mark is uneven in depth (yellow arrows).
The serial number is for a screw back, but there was 'reissues' given out at the end of the war for the Victory parade, (and I would assume for various other victory functions at that time) these do not have a 'D' marked on them.
Here is a link from another forum on the topic:
http://www.warrelics.eu/forum/orders-medals-badges-decorations-corresponding-documents/confused-about-order-red-banner-26467/
Regards,