The 64 Electrical Manual (AM0003, pg 13) show the bracket, 370805-S100, attached by a hex head sheet metal screw (42127-S8) to a "lip" on the upper LH dash above the fuse block used for the main under dash harness.
The 65 Electrical Manual (AM0008, pg 23) shows the same bracket attached by a pan head sheet metal screw (358735-S2) to the upper rear portion of the LH vent used for the turn signal harness up the steering column. No effective dates are visible on either page.
The lower LH edge of the dash location by the parking brake, is very possible given the hardware shown in the original post. There obviously is a build time, early 65, and plant specific, San Jose, for this application. That is stated so as to warn others to ask.
Jim