My original plastic one is on 9R02R156640 built 3/18/69 in San Jose.
Ok tool a look at my San Jose pictures from 69 Mustangs and found the following (of course allot of them did not include a good picture of that particular area
With metal attachment throttle cables
114855
120271
125360
131545
146511
148866
With plastic attachment throttle cables
104037 (guessing this one has been replaced since it falls outside the pattern by allot of time)
156440
156640 (yours)
157240
Not a big sample so far but the pattern did appear
Again for those viewing this is
69 SAN JOSE ONLY in this post