I have done some more digging around (WireShark is amazing!) and I
have gotten past a big initial hurdle: I was building the signature
base string wrong (building it, then setting more parameters, which
should have been part of the base string in the first place).
As a sanity check, at this point
Some more debug output for completeness:
Since this is multipart form data, the oauth signature base string
would be just
httpMethod + +
url_encode( base_uri ) + +
sorted_query_params.each { | k, v |
url_encode ( k ) + %3D +
url_encode ( v )
}.join(%26)
where the params is
