"The common chip is the inlay-lifting Burt chip (I do have a nagging feeling that the Burt chip might actually be a pre 1911 Whitehead & Hoag inlay USPC chip)"

I have this in my records. I think it is right.
Burt - Alonzo Burt started Portland Billiard Ball Co in 1912 - 1st chips made in late 1920's.