In my ‘quick buying guide’ to Challenge Timer (‘Bullhead’) chronographs I have described how the original ‘base metal’ cases have a satin finish rather than being polished and shiny – these are typically the 67-9011 models. The only highly polished finish is found on the one full stainless steel model – the 67-9356, which is easy to spot since it’s an octagonal design.
For reference here are three images – the first two are from Citizen’s own historical site and the satin finish is clearly shown (note the original bracelet types and different crown sizes) :
And here’s a third example, this time from what I call the ‘museum’ book:
Sometimes refurbished models have been polished, and there are examples of gold and black coated cases being de-plated and then nickel plated and highly polished.
I’ll add these three pics to the chronograph article.