Here’s a small caption out of the users manual that has a 5-page document on the factory midi interface:

“Patch transmit – “write/reset” switch (page 2)

The program enable switch also allows you to transfer patches from the master OB-8 to the slave OB-8.  (NOTE: Memory-Protect must be off on the slave OB-8).  In page 1 on the master OB-8, select patch D-1.  Now, enter page 2 and press the write button on the master OB-8.  After a short delay, the write LED will light, indicating that the program patch D-1 has been transferred from the memory of the master OB-8 to the memory location D-1 of the slave OB-8.  To play this patch on the slave OB-8, you must return to page 1 and reselect patch D-1, or select a different patch on the master OB-8 then select D-1.  Now both OB-8’s will play patch D-1.”

Now, I know that wasn’t very helpful as far as transmitting sysex data, but that was the only caption related to anything about transferring patches.  (plus I typed all that out!)  It is basically referring to transmission of patches between two OB-8’s so I can’t conclude if this is related in any way to getting the sysex data back in.