Hi Jim,
yep the P6303 looks quite 2martial", but both pth probes (6302 and
6303) are great tools for current measurement applications.
BTW: The other manufacturers I know for current probes (Chauvin-Arnoux,
Hartmann&Braun, Merlin-Gerin, just to name a few) choose a very similar
design for their higher amperage probes. I am not shure, but may be you
don not have much design choice when you aim for a split-core, high amp
unit.
The manuals are AFAIK downloadable at bama.sbc.edu (and it's mirror)
hth,
Andreas