This is a Luger that has been around.
Started life as an Imperial Erfurt, WW1.
Was rejected and repaired, (crown RC).
Had original date ground off in 1920 during the Weimar era.
Somehow got an early Swiss shield on the chamber.
Has a Swiss target long barrel.
And has those little sunbursts on the upper and lower as well. E German?
Also has *2* sets of regimental marks on the grip strap, one polished out, and a second added that is R.R. and some numbers, (Reiter Regiment, horseback unit)