[rzzzt]

Do you know if Commodore manufactured any two styles of these in parallel intentionally, or if this was a matter of making use of existing housing/keyboard assembly/motherboards?

The corresponding article on C64 Wiki says that side symbol keyboards were used during the first year of production, and also includes a picture of the top glyph version: https://www.c64-wiki.com/wiki/C64C

[xenomachina]

My understanding is that the "main line" was breadbin, 64C with front glyphs, then 64C with top glyphs. The Aldi 64 was concurrent with the breadbin, but mysteriously used the keys from the early 64C. The 64G was concurrent with the late 64C. The Aldi and 64G were only available in a relatively small area (mostly Germany), rather than internationally.

Commodore was notorious for mixing and matching parts, though. Even the very early breadbin 64s would sometimes ship with VIC-20 function keys (orange instead of dark gray) and vice-versa. I don't know if this was due to poor quality control, or an intentionally sloppy supply chain management. Perhaps a combination of both.

The 64G especially looks like they were scrambling to meet demand any way they could, as the key colors and even the LED colors vary. I'm guessing the beige breadbin was used to increase production speed by taking the old breadbin injection molds out of retirement. They aren't old cases that they had in inventory, because breadbins weren't that color previously.