If in fact, the clip is 377119-S32, it's also used on 64 thru 66 Mustangs for the same fuel line retaining.
Jim
Clip, 377119-S2 (note, it's -S2, and is not serviced), is shown in the illustrated section of "Ford Car Parts" (aka MPC) as used in 67 and 68 heater control power cable. I will add it to the hardware spreadsheets (after I finish a couple of other projects).
Available AMK.