Three years ago we found a bottle of Carnu in the wall. I posted a thread about it. In the thread, I posted SC Johnson’s reply to my query:
Please know Johnson’s Carnu with the specific label design shown in the picture you provided, was available in brown bottles until roughly 1944. We believe the red cap is original to your bottle of Carnu, as these caps were made from Bakelite - the first synthetic plastic commercially available.