That pretty much sums it up.This is akin to saying, my friend would like to buy a Ford, can anyone help him?
There are a multitude of knowledgeable Mauser folks here, but you'd have to provide some information. Is he looking at a custom rifle? A military rifle?
The guy who knows a lot about a 1910 Model T, probably doesn't know much about a 1932 Roadster, probably doesn't know much about a 71 Highboy.
I’ll find outThat pretty much sums it up.
Just be aware that there are a couple of different variants/models of Mauser rifles in the 7x57mm that were used by Spain, Mexico and a plethora of other countries. Do you want a Small Ring Mauser or do you want a Large Ring Mauser? That is the question.
Jeremy