Yes, the owner who had it before me told me it was orderd from W R by an australian target shooter named J T Lake from Adelaide. He ordered it at the end of his career.
Yes the barrel has marks with 303 00000xxx(shall take a closer look.) and a crown-symbol side of the number there. Same crown are stamped on the handle for repeat the action. And serialnr under it too. Matches the one stamped above the action.
So the barrel seems to be original.
The width of the barrel, hmm it is me that takes measures in centimeters because we use it here in Sweden and Europe.
But yes one inch is 25,4 mm and the barrel is 23 mm thick.

So they bought actions from Mauser ? Thought bigger companies made their own stuff. But this definetley looks like Mauser-action and it is a 98 for sure. Had an old Mauser 96 before, so the difference is clear to me.