I know a lot about Lugers and the main thing I absolutely am certain of is they are not for a new gunner. They are unsafe guns and need to be very carefully handled. The date is usually easy to find as its prominently marked .The maker is a bit harder as the logo is in code as in the numeral 42 indicates : Mauser, Berlin, is just one example. I strongly urge your friend to become more acquainted with guns which are more user friendly IE: a nice S&W wheel gun. If he just has to have a Luger please get proper handling training before he loads it.
I know a man who didn't, and ended up very dead, do to a Negligent Discharge! He shot himself in the thigh and he bled to death in practically no time at all.