Thanks for the info guys... Upon research I found several holes in the story my mom told me (that she said my great aunt told her) - so I went straight to my great aunt with the research that I found.
NOT GERMAN BUT RUSSIAN>>>>
Actually talking with my great aunt here is what I have pieced together.. And where we stand.
Her father was a DR in the US 7th ARMY in WWII
*** In a lead role in Operation Undertone, the Seventh Army fought its way across the Rhine into Germany, captured Nuremberg and then Munich. Finally it crossed the Brenner Pass and made contact with Lieutenant General Lucian Truscott's U.S. Fifth Army at Vipiteno - once again on Italian soil.
In less than nine months of continuous fighting, the Seventh Army had advanced over 1,000 miles and for varying times had commanded 24 U.S. and Allied divisions, including the 3rd, 36th, 42nd, 44th, 45th, 63rd, 70th, 100th, and 103rd Infantry Divisions. ***
Sometime in the final months of the war he encountered a Russian officer at a MASH camp where he served. My Great Aunt states that her father said he treated an officer (she always assumed it was a German Officer), the officer gifted the pistol to him. (the story has changed to the officer was a patient and the officer was a fellow DR. - so I am not sure which one) He was not allowed to bring it back with the magazine. Later in his like (40s - 50s) one of his US patients heard the story and was able to obtain an authentic magazine, which completed the pistol.
Only thing I could find on a Tarasov MM was the following link to some medical articles written in Moscow in the 1960s (which would help support the vbersion where he was a fellow Dr.)https://europepmc.org/search?query=Tarasov%20MM