thanks to SKB and Toby...baker's was correct. a quick search pulled up a 2019 VGJ article by james reynolds, in which he goes thru several likely problem areas and gives his analysis of the design.
my question was based on my I. Hollis & sons 12 gauge, which has this type ejectors. it's a WR actioned gun, and i had supposed the deeley system would be the most likely usage. both ejectors work separately, but not always in tandem. reynold's article gives useful trouble shooting suggestions for that possibility.
https://www.vintageguns.co.uk/magazine/the-baker-ejector
