6" starrett firm joint caliper style unknown ???

6" starrett firm joint caliper style unknown ???

One layout caliper. Made by Starrett in the USA. These are 6" calipers, I don't know what style these are. One end has a sharp point, the other end turns at a right angle to the inside ( toward the point end). These are in good condition. There is some very minor surface rust, but most of the discoloration is a cosmoline type protectant