Found a couple more

[Brutalfly]

I thought these were cool so I had to get them. Probably should not get to many more

 

[Sitcoms]

The one on the left was a CERTO (or similar brand) fruit pectin bottle. You would use it when making jams/jellies to help solidify the texture. The bottle would contain 2 doses of the pectin, and as such you would pour until the line (in your case 1/2 cup). Royal Crown was a fairly big cola name that sold nationwide at one time - check the bottom, it might have a date code depending on the manufacturer.

 

[Brutalfly]

The one on the left was a CERTO (or similar brand) fruit pectin bottle. You would use it when making jams/jellies to help solidify the texture. The bottle would contain 2 doses of the pectin, and as such you would pour until the line (in your case 1/2 cup). Royal Crown was a fairly big cola name that sold nationwide at one time - check the bottom, it might have a date code depending on the manufacturer.

Thank you for them info.
The bottle says 1936 for them date on it.

 

[Foreshore9]

I have a few Certo's cool bottles !