Well, so much for getting that bracket. I got a response today from them...
Thank you for your email. Several years ago Mr. Jones made a large circular bracket similar to the J-35 called J-1000, this bracket was used primarily
For larger format cameras. The circular ring had an opening of approximate 8 or 9 inches in the center. Unfortunately this bracket is no longer manufactured and
No replacements parts are available.
I am sorry we do not have any brackets that will support the Pentax 6x7 at this time. If you have any additional questions or if I may be of further assistance please
Email or call anytime.