2.) Is wiring clip ("P"-shaped) 377846-S reproduced? It looks a lot similar to the ones used on later 67-8 Hood turn signal lights, Osborn manual has those as 377774-S so Ford saying they are different.
Clip 377846-S is not reproduced. It is sort of common for 64 thru 67 Mustangs, with your best source of used clips being 64 to 66 Hardtops where two are used in the trunk for wiring (also 64-66 Convertibles and one each in 65-66 Fastbacks). The 67 application is the console and fog lamps. Description - 1 5/8L,1/2W,1/16T,11/32H,BLK PLSTC
Clip 377774-S is used on 67-68 hood mounted turn signals only. Description - 1.0L,1/2W,5/16LOOP,0.413X0.627MTG GRIP,0.210 HOLE
AMK and other vendors are selling the 379061-S clips for the Fog Light Wires at the support braces but I'm not finding the looped slyle (or hoop style) anywhere yet. BTW, beware of these 379061 clips at Champion Mustang...they are selling the wrong ones (found out the hard way when I went to slide them on)
Clip 379061-S is still being sold by AMK.
Jim