What on earth is the problem with non-matching bolts? In the real words of Armourers shops around the world, this is what you do. You check the bolt that is already fitted OR take another bolt - new or good used - off the shelf, then fit it according to the simple (?) instructions regularly repeated on this forum. That been done, then you clean off the back of the bolt and then do one of two things. A) put it in the special jig in the pantograph engraving table and engrave the rifle serial number or; B) Put it onto the leather jaw clamp vice and stamp the new number into it.
Label old bolt with UNCHECKED label ready to go to calibration lab.
There, that wasn't toooooo difficult was it?