It's been a very very long time since I've worked on this car but I don't remember it ever having a shut off valve. Was that something some 4's had & other's didn't? ..a owner add on perhaps?
Geo, I faintly remember now there was a flex hose connected there, however, looking at a couple different diagrams of the piping layout, they show the LH brake line going from the 4 way sorta tucked along the bottom cross brace just in front of the oil pan then to the caliper. No diagrams I can find even show that bracket so I guess a routing change implemented at some point. Seems it could have been a little farther forward maybe..
Anyway, in your pic (thanks for that by the way) it looks like the hard pipe may be following the side rail to the front then over to to 4way? Really hard to tell but is the line going thru the bracket hole from the bottom side or the top?