A GOOD, WORKING EXTENSIOMETER
MANUFACTURER: B.C. AMES

WITH DIAL MICROMETER AND THE ORIGINAL WOOD BOX
Markings "M-1083 EXTENSOMETER HSP BLL BOLT"

It's straight. It's working.  It's smooth and the micrometer is nice.
4.5" and 7" arms
The spring is good.  No slop. The dial needle moves smoothly.
Shipping in the connected usa states is $12.
Regards,
Paul