I re-attached the pictures I had posted in this thread here again, in case the rifle ever surfaces again and to make a clear connection.
The company Old Arms of Idaho proofed that it is a serious address for any collector. They did the only correct thing one can do with an active auction which can't be ended - they added the note to the auction that this rifle is not original and won't be sold.
This is something which quite a lot of companies would not have done and is a clear statement to any collector out there, that they want to be a reliable source for customers.
Many thanks for this step, best luck with the rest of the auctions (in case the others have not noticed it: they are selling an extremely nice BNZ 45 K98krifle which appears to be all original and correct, especially since it is the very rare variant with a walnut stock and a laminated handguard!) and I hope you will get your money back on the "M1903A4" rifle!