mxm190 - Yes, you're right. You can more easily hear & trace the influence of jump blues in his playing, but that's correct. Walter was likely influenced by anything he heard & liked, he was one of those players that you can tell soaked in a lot, aside from the blues harp tradition before him.
Im from South Louisiana, not far from where Walter came up. One type of musical infuence of Little Walter that you guys left out is Zydeco. This is a branch of cajun music that was more prevailant in the creole black people of all parts of La. back then. Nowa days its loved and played by both blacks and whites, and is a mixture of blues/cajun/creole/southern swing. Look up Clifton Chanier this was more than likely Little Walters infuence aside from blues and swing that helped mold his style.