110% with you on that.

I'm suspecting that machine work has overtaken the hand fitting of the Rigby Mauser.

Of course, way back in the day of the first Rigby/Mauser relationship, meaning turn of the 19th/20th Centuries, Mauser more or less built the Rigby rifles to their specification from start to finish.
Surely they used some sort of replicating machinery to work the metal (of course) and also the stocking.
Now, how much handwork was employed to finish the product is open to conjecture.
That said, one would naturally expect that a modern Rigby produced Mauser would have inletting and finishing more than equal to the, let's say, military production rifles of the '30s.
The fitting around the bottom metal of these sporters is not all that impressive with the price in mind.
In my most humble opinion, any rifle with a pricetag over $4K should not allow any criticism of the wood to metal fit and finish.