Philco was an american manufacturer of radio and TV sets. Their 'cathedral style' radios from the 1930s were very famous. Philco did nor produce tubes themselves. They sourced them from other manufacturers and applied their own branding.
A similar style box was also used for other tube sizes Like Octals and 9-Pin miniature tubes:
A 6AX4 box:
A later box style, again 6AX4s in two dlightly different alterations of this style:
These boxes had prominatly displayed quality and performance claims:
The company wet trough a lot of changes throughout it's history. After the radio era they produced TV sets and were actually quite famous for very unusually and modern styles. In the 1950ies they also developed and manufactured computers and even electronics for space missions.
Here two two boxes of a very late style:
Ford sold Philco to GTE (who also used ot own Sylvania) who then sold it to Philips. Philips bought Philco 1981 for the name brand. Due to the similarity of the names Philips could not sell products under their name before they axquired Philco. That's why Philips used different brands like Magnavox and Norelco before that time.