A "new" P-08, byf 42

[sepolvora]

Dear sirs:
I've been one of the most un-grateful members of this forum.
Several years ago, I was given a "portuguese" Luger that you helped me to identificate and look for te important numbers and markings in the right spot.
Even I learned more than a few things about Luger and history here, I have been absent a long time.
But, a few weeks ago, my father in law decided (due to his declinign health) to appoint me as the caretaker for the rest of his weapons, so I am the humble carer of his Sauer Drilling, another Luger and a P-38.

So this is the point: I would like to get some help to identificate a Luger having the following marks:
It's a nicely blued 9mm, in very good state , except for the wear on the left side of the barrel end and in the dismsntle palte on the left.
It's marked "byf" "42" on the top, a 4 digit number xx09.
At the front, under the barrel , there is a cursive M.
At the right side is stamped the little spreaded eagle (twice, one is fainted) and under that is the number 135.
There is another, tiny eagle, on the left siode of the barrel.
It came with three "XO 37" magazines, charging tool and her flap holster, much nicer them the one I have.

As I said some time ago here, Iam not a collector, just a shooter, my particular craze is about mauser rifles, but now I am more th emerrier to provide room and board for these german ladies.

The picture is no marvel, but I've seen worse.

Many thanks in advance for your advice and peace to the world.