Roy (Underhill) had the basic shape of the handles turned for us by a local chair maker. I shaped mine and added a spacer so I could get my stubbie fingers around the grip. I put a thread insert on the back side of the spacer to aid in mountng them to the chest.
This picture shows the profile I came up with.
-- The expectations of life depend upon diligence; the mechanic that would perfect his work must first sharpen his tools. Confucius, 经过艰苦的努力的梦想可以成真