WT6b Phonology revision

DOH!

The WT6b phonology I posted recently included the following
slightly incorrect renderings into X-SAMPA

Roman:   s^h z^h r   z"
X-SAMPA: C   j\  r`  r`_r

However it should have been...
X-SAMPA: s\  z\  r\  r\_r

i.e.
The r` and r`_r should be r\ and r\_r
The C and j\ should be s\ and z\

My apologies for this, ISTR it was quite late when I was typing
them in based on (correct) handwritten notes in IPA and things
must have gotten a little blurry (plus I'm a natural doofus).  In
light of these minor (?) corrections, please let me restate a
question I asked at the time...

Is /r\_r/ too close to /z\/ given the presence of the eight
similar fricatives? (/s/ /z/ /S/ /Z/ /s`/ /z`/ /s\/ /z\/)

It is supposed to represent a sound halfway between /r\/ and /z\/,
is it even the correct choice of symbol?  Do I mean /r\_r_-/, or
would that be taking things just too far?

Thanks btw to the amazing Mr Weir for his brief "How to build a
large vowel system" tutorial <G>  Now all I need to do is find out
what all of those symbols (and terms) sound like!  I can read and
transcribe consonants fairly well (IMVVVHO), but I don't really
have very much of a clue at all when it comes to vowels.  Can
anyone suggest a good webpage (with audio files if possible?)
where I can get a better grounding.