Transcribing skip it by big Walter Horton

Hi

I'm trying to transcribe all of big Walter's solo on skip it, off his can't keep lovin' you album. I'm using a standard c Richter tuned harmonica because I think the song is in Dm. Some of the parts I play sound right but just a little bit off, I don't know if it's because I'm using the wrong harmonica or just not listening well enough.

The single note lines I do correctly, but some of the tones he uses like in the beginning are hard to decipher what techniques he's using or maybe if it's just the settings on his amp. Sometimes I can't tell if he's using double stops in the beginning or if it's just distortion especially the 4 and 5 draws.

Am I using the right harp, and is the distortion kind of making him sound like he's playing dirty notes when he's not?