You might try a GBOF Meat Fuzz or perhaps go PNP Germanium with Bias or create your own with a GBOF board. That said so people know what we are talking about here is an image.
Any info I find appear to be educated guesses. Lots of Heathkit TA-28 references.
There is some info here that sounds about right:
I would think a cheap early fuzz like the TA-28 with that particular type of guitar playing through a breaking up amp should be damn close. I think this is also a good reason for the tone of his Wah Wah stuff.
TA-28 Video for reference.
For other peoples reference here is a video that shows his base tone and then the Fuzz he uses for solos.