And the good news is according to the 70 FSM that diode{part # 2983595} was also used in the other body styles so finding a used one might not be as hard as you think..... Or if originality is'nt a factor you can always get one from an electronics store like radio shack, install some connetors and wrap it with cloth tape and nobody but you will know... .. .......... Now, on the headlight delay relay itself I've found some more pics so here you go... Here's an NOS 70 E-body relay... ....And the part number and date code on the mounting tab... ....Now for comparison here's an nos 70 B body piece... ....And lastely an NOS 70 C body relay... ....Now...If you look closely the actual relay insert and casing is the same across the board...It's the mounting hardware that's different and the C body piece is real close to the E body part....So again, if originality was'nt a factor or you had a shot insert you could swap the guts, or just use the other body style relays and it would still do the job.....
Or if originality is'nt a factor you can always get one from an electronics store like radio shack, install some connetors and wrap it with cloth tape and nobody but you will know... 
.. 
..........
....And the part number and date code on the mounting tab... 
....Now for comparison here's an nos 70 B body piece... 
....And lastely an NOS 70 C body relay... 
....Now...If you look closely the actual relay insert and casing is the same across the board...It's the mounting hardware that's different and the C body piece is real close to the E body part....So again, if originality was'nt a factor or you had a shot insert you could swap the guts, or just use the other body style relays and it would still do the job..... 
