I own a twin brother to your new Mauser......I love it!! Mine makes it to the range quite often, and I only wish that I could be as accurate as it is!!
I was unhappy with the grips, so I set out to purchase another set of Mauser Parabellum grips to modify, and keep my originals as they are. Well, new/good/poor Mauser P08 grips were just not available for purchase......believe me, I looked hard. To make a long story short, I sent my grips to Hugh Clark(now retired) and he corrected the profile and recheckered them. He did a beautiful job, and now they not only look perfect, they feel perfect. Huge difference.
Perhaps you could get Jim Solomon to build you a thinner pair, or re-profile yours, I can't say. Congrats on your new Luger, now run some rounds through it and give us a report.