Problem solved. There are two rubber o-rings that seal the low pressure return 'block' to the valve body on the top of the steering gear box. I didn't recognize them for what they were because they were so hard, crushed and brittle. I'd swear they were some form of metal seal. After a recommendation from the guys who did most of the resto work on the car I took the block to the local NAPA store and matched up the rings and the problem is solved. I did have to remove the battery and battery tray to get access to the bolts but all in all it was about an hour job. $1.58 in parts and it's now leak free. As a tip, use a bit of Vaseline to hold the rings in place while the block is being bolted up.
