very good, although too many words for me
You are correct - Mauser with the code name of S/42 and made in 1938
Note that every 10,000 guns, a new suffix started, some years they started at no suffix, then "a" etc up to 'z' - so your " i " or ' lower case L " would be like the 70,000 or more.
BTW, the suffix is not the same on the gun and the magazine, and it looks like it was added (changed to 70) - so value is not the same for a 'force matched' than a factory matched.
NOTE 2 - that an import marked gun will turn off some folks - some saying its a shooter only
My feeling is that WW2 guns (even pre-but nazi marked) are much better sellers - so I would say that its worth around $1000 to $1300
Ed