My updated spin on statting up the PCs from The Great Molasses Flood based on a closer reading of the rules, specifically choosing listed Traits:

Lorenzo Caligari
A firefighter and veteran; second-generation Italian immigrant. He has Boundless Endurance and the Secret, “Why doesn’t Lorenzo talk about his older brother Salvatore?”

Body: 3

Mind: 3

Charm: 1

Superlative Trait: Boundless Endurance
Trait: Always Cautious

Trait: Extra Quick

Trait: Associate (Italian immigrant community member)
Secret: “Why doesn’t Lorenzo talk about his older brother Salvatore?”

Sam Michael
A sailor and veteran on leave. He has Uncanny Insights and the Secret, “Why does Sam stay at sea despite the difficulties and limitations?”

Body: 2

Mind: 3

Charm: 2
Superlative Trait: Uncanny Insights (where is this defined?)
Trait: Associate (fellow sailor on leave)
Trait: Extra Aware

Trait: Extra Coordinated

Secret: “Why does Sam stay at sea despite the difficulties and limitations?”

Harmony Wright
An activist for the Socialist Party of Boston. She has Inner Peace and the Secret, “Why did Harmony come to Boston?”

Body: 2

Mind: 2

Charm: 3

Superlative Trait: Inner Peace

Trait: Extra Convincing

Trait: Associate (fellow Socialist Party of Boston member or sympathiser)

Trait: Extra Knowledgeable

Secret: “Why did Harmony come to Boston?”

TBD: Negative traits, Skills, Quirks and Ties, not to mention Resources/Setbacks and Edges.
Is this on the money or have I missed something?

You've answered most of this correctly! The example characters on the Rosette page are scans of sheets from our home game. Most of the differences between your reconstructions and the official stats for The Great Molasses Flood are things that would have been tricky to figure out from listening. As an example:

Sam Michaels

Body 3, Mind 2, Charm 2

He has Uncanny Insights (S, from the Companion and your link), Sharing Personality (+, from the Companion; spend Focus to let someone else use a Resource of yours), Always Composed (+), Multitasker (+), Not So Attractive (-), Overgenerous (-, from the Companion; can't boost with a Tie when you have Focus)

His skills are Poetry, Rigging, Ship Engineering, Coordinating People, and Code-Switching. His quirks are Always Belowdecks, Old Timer, and Bendy Gender. He started with the Resources: Experience in commercial shipping/hauling and Fine Tool (a multitool/pocketknife).

You've got each character having an Associate, which would make sense, but only Harmony ended up picking Associate as a Trait and it didn't come up in play. The others were still able to have those connections to NPCs, but without the Trait they didn't get the benefit of using an Associate's character properties as their own.

We'll make a note to write up and share some more example characters in a more readable form to help give a better idea of how we're envisioning them being built!

It took us a bit, but we've uploaded three example starting characters: a mundane character (Sam), a fantasy character, and a sci-fi character.