Found these on the wiki. I'm not an expert on these in-board connections but maybe someone could use these for reference.
http://www.midibox.org/dokuwiki/lib/exe/fetch.php?media=wilba_mb_seq:wilba_mbseq_pcb.pdf
http://www.midibox.org/dokuwiki/lib/exe/fetch.php?media=wilba_mb_seq:wilba_mbseq_pcb_dimensioned.pdf