There was a period when Mauser rifles and contemporaries were produced without forend checkering. A styling option l suppose. Note also that this example does not show cross bolts. An extra under barrel recoil lug was considered sufficient. I had a 425 WR done in this way too. No splitting apparent on either rifle, but l would like to add period appropriate brass cross bolts if l keep it.
I'm toying with the idea of letting it go, because l have a cogswell and Harrison 375 with cocking piece peep sight that l really like and prefer. The idea of keeping white elephants / safe queens bothers me a little. Hence the original question of what is it worth to a collector.