A customer has requested you service his favorite family heirloom, a World War II Arisaka Type 2 Paratrooper rifle (also called aTERA - Teishin Rakkasan Assault/Raiding Paratrooper).

After you take note of the serial number, you notice the retaining pin used to secure the barrel/forearm assembly to the receiver appears to be missing the D-ring. The D-ring is intended to aid the shooter in pulling the wedge to disassemble the rifle for transportation. After bringing it to the customer's attention, he has requested you create the D-ring.

As this is a relatively rare firearm, finding reference materials can be very challenging. Use the discussion to brainstorm answers.

1. If you can't find a physical sample or blueprint of the part you are trying to create, how else can you get measurements for the part?
2. How might you determine the material to construct the part from?
3. How would you test the part for quality?
4. And where you get reference?