This is a Datsun 60-series Transmission 4-speed case that was modified to fit five Hewland Mark 4-8-9 gears. It was built by Dan Hall of Portland, Oregon, USA and used in SCCA racing.
New they were $3500-4000 USD.
Discussion: http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=43428