I think you should buy a 2nd B or C grade P7 to HC, and not change the looks of yours so drastically. Your finish is original and in great condition, so why HC? I prefer a dark finish on a tactical weapon unless the weapon is being used in a harsh environment or the user prespires a lot while carrying.
This is my C grade from HK Specialists, and yes, this is my primary carry gun. I could carry my A grade just the same, but I'd rather not risk buggering it up. I regret selling the C grade in my avatar to fund my A grade, but I guess that sometimes we have to make concessions. As a rule one should never sell one's HKs; you will undoubtedly regret it later.