Help finding pipe adapter

[u/omicron_pi]

I have a Malm Zircon 38 wood burning fireplace / stove. It comes with a 9” flue pipe (actually 8 7/8” OD) and a 9-to-10 adapter that is meant to slip fit into a 10” class A double-walled chimney. I have the Selkirk 10” chimney pipe system but the wider end of the Malm adapter is just barely too big to fit inside! Maybe by 1/8-1/4” of diameter or less.

I need an adapter that can slip fit inside the 10” chimney. Does anyone have a recommendation for a specific product or know of a company that could custom fabricate this for me?