some CG phonology qs

This is probably a bit off-topic again, and I apologize, but... =)

Maybe I've just been reading the wrong material, I don't know, but I
can't seem to find some solid information I've been looking for for
quite awhile.
From IE, T changed to theta/thorn/"th" in CG. Now, did CG also have
an eth sound? For instance, in CG, would it have originally been
faðar and only later fadar, or would it have been both [depending on
the dialect]? I thought I read somewhere that the IE>CG "d" in CG was
originally an eth sound (later staying eth in, say, OI, OE, etc. and
changing to "d" in [High?] German), but everything I've read doesn't
state that explicitly - usually the case is that whatever I read uses
different symbols to represent the sounds and never comes out and says
what each sound is. Basically what I am trying to find out is what
the phonological inventory of CG was, and therefore what was carried
into the daughter languages. Anyone happen to have any
tables/charts/graphs handy? I would love you.
Right now I'm working on a little project about how Modern High German
developed out of 'the original', but I've been meaning to know for my
own personal reference anyway for quite awhile.

TiA!