Luger P08 Double stamped 1920.......need help!!

I have a chance at a purchasing a very nice DWM P08 Luger in 9mm with 4" barrel. It is stamped 1920 for year of manufacture and above that stamp on the breech is the addition of the same 1920 stamp....I guess this is the gov't acceptance stamp. Are the 1920 manufacture usually reworks and re-blued? The luger is in as new condition and all serial #'s match, bore is as good as it gets. It comes with 2 serial # matching magazines, serial # matching take-down tool and a very, very nice serial # matching holster with police style strap with the additional stamps of Robert Larsen, Berlin, 1935.
I'm curious to what the value of this rig would be as I'm not that familiar with Lugers....I have read that some of these were a hodge podge of parts re-numbered to match...not sure if this is true.
Sorry don't know how to upload pictures.
Your thoughts would be very welcome.

If it's a 1920 double date with 4 inch barrel then it's a rework, most likely reblued and was issued to a police department. The Blue book lists it at 95% finish at $875. The holster would add at least another $100 to the package. So a value of at least $1000.

Once again you can send me some pics by email and I'll put them up...check your messages for PM.

After WWi Germany was restricted to a certain number and types of military. Small arms were repaired, refurbished and updated if necessary, and then stamped for the years 1920, 21, 22.
Until enough were produced to re-equip the shrunken military. All others were supposed to be destroyed. My Amberg GEW98 had the sight changed to agree with the new cartridge, and was reblued. It is, marked 1920, of course, non matching.