@H22A4 That was something I have been curious about myself! I was starting to believe that it may be a very late build. There are some other little oddities that I've been discovering - compared to some the research/information I've come across as I've been working on it. One example is the head... somewhere I read that the non-tube/tapered-seat head was introduced in '76 other places I've seen it as listed as '75... I have the tapered-seat. On the yellow '74 I have the tubes... so that was throwing me off. I pondered whether if the lenses were offered as an option and ordered as part of the "custom" in the Valiant Custom badging... :P ?
Honestly, I have been so concerned with getting it all going mechanically I haven't really dug in to the history. I do have the original punch card and there are hints of a build sheet I've seen tucked under the glove box. I will have to dig them out and do some more investigating. I will post some pictures!