That does not appear to be the original finish and I seem to see some pitting under the bluing, which indicates a rework. The grips are obviously not original and the only 9mm P's that Mauser made were the "Red 9" guns of WWI, which were full length.
The gun appears to be one of those imported from China, buffed down and reblued plus rebored and rechambered to 9mm by the importer. It is a fair example, and a shooter, but has little collector value. They are OK at a reasonable price, but sometimes folks pay a bit too much (something I am sure never happens with Lugers). ;>
BTW, be very careful of "Red 9" pistols; almost all I have seen on the market recently were fakes.
Jim