Yep, the recesses aren't deep enough (or finished enough) to use for anything remotely precise ...
I totally agree that they will be useful as parallels and they can be used in either orientation in that function. I just didn't want to look completely stupid for using some elegant tool as a parallel just because I didn't bother to ask what I had
... it would be like using a sine bar as a parallel!
Thanks all,
Saands