This post shows a the back of the SCA CD 133.1 Dec 19 1871 telegraph bullet that was found between 1973 and 1975 on the Chicago Northwestern Railroad as it ran East out of Boone, Iowa toward Ames, Iowa. Five SCA and seven Aqua CD 133.1's were recovered. Details are as follows:

CD-133.1 Patent / Dec 19 1871 (Front Skirt) - 3 /A (Back Skirt Mold Style Number & Letter - Light SCA (Microbubbles & Cull Stones) - Measurements: 64 mm Wide x 89 mm Height. (Light Embossing)

This post shows the front of the SCA CD 133.1 Dec 19 1871 which was found in Iowa [id=614294556].

Note: I left the rust on the back wire groove on the insulator to remind me of the heavy iron wire that was found on this CD 133.1.