Scoping a Mauser can be done in a couple of different ways. From
fairly easy to advanced skills required. Which ever way you decide
choose a good quality scope for the caliber and range you intend
on shooting. A 9x scope is not for 600yard shots and a 16x scope
is overkill for 100yard shots.

Click image to see Drill n' Tap jig on Midways site.
Receiver mounting- To mount your scope center over the Receiver
the receiver must be drilled and taped for the mounts or scope rail
and the bolt handle will have to be forged [ bent down or cut off
and a new handle welded on]. Your gunsmith has a jig that is designed
to position the rail dead center over the receiver this is not something
you should attempt without the proper tools or knowledge as if the
holes aren't lined up perfect you don't get a second chance. Another
way to archive this without drilling is to use an ATI scout stock
which has an upper hand guard that comes back over the receiver
to mount the scope to but accuracy suffers with this configuration.
If you are using the military barrel you can buy a mount that lets
you replace the rear sites with a scope mount to be used with LER
[ long eye relief or pistol scopes ] scopes. Its a fairly easy process
and achieves good results but is not as desirable as having the
scope mounted over the receiver.