Voyager Painted Keys- a 16C with triple personality

[Allen]

I have seen occasional talk regarding Voyager keys being painted.

Here is a photo of a 1986 16C with BOTH 12C and 11c(15c) background.
The OCT key came out the best of all the photos. On the 12C it is a % sign, while on the 11/15c it is the TAN key. The transparency is set to 20% for each of the other keys in the 'unpainted' overlay to show the approximate lettering underneath the 16C paint.

My Voyager collection key status:

1982 10c regular keys

1982 11c regular keys

1984 15c has 12c keys underneath

1984 12c has 15c keys underneath

1986 16c has 12c AND 15c keys underneath

1986 12c has 15c key underneath

1988 12c has 15c keys underneath (both 1988 models) 

[Frank Boehm (Germany)]

I wonder if it wouldn't have been cheaper to use blank keys instead instead of coating *and* printing them?