Technical Drawing/Drafting

Created by cmalco on 12 March, 2018

Hey guys, I have a couple of symbols here that are from some older blueprints so the conventions might be out of date but I can't really figure out what these are telling me.

Dimensions have been removed because of NDA stuff. Thanks for any insight!

A former teacher of mine said the following is called a "dim-jog" line (the two arrows referencing the centerline) but I'm not sure what the number in the bubble means or what the symbol is telling me.

Post other weird/archaic symbols if you're confused