Info needed on Rudolf Walther

Hi Guys, new to the forum, I'm looking for information or perhaps a way to proceed in researching Rudolf Walther, just doing a few quick German google searches I have found 3 guys of that name, the guy I'm looking for was a Fähnrich in around 1938-41, of the 3 I have found one was an Oberst Leutnant in 1942, I believe I can rule him out as he has too high a rank for my guy, the other two have possibilities, one was an Observer in bombers in 1944 and had a rank of Oberleutnant, I can't find out anything else about him, the 3rd and last guy I have found was posted to Russia in JG52 III in May 1943 at a Leutnant, after researching the time it took for a Fähnrich to become a fully fledged pilot at least 18 months I believe, this guy seems my best hope, is there an archive I can look at online where I can find out more about these last two guys or any research that I may be able to handle myself, I'm not a fluent German speaker but I can make myself understood if it is in Germany.

Hope you guys can help me

Cheers

Gary