If someone could ID the plastic reservoir part I would very grateful Bap Geon can't even tell me what the hell it is 😑

The part circled says something about dot 3

 

It's the reservoir for the ABS modulator.

The part number for the reservoir is 57019-ST5-000.

The part number for the entire modulator assembly, including the accumulator, is 57110-SV1-A04.

 

I visit Honda Parts Now when I need to learn a given Honda part number, or I want to buy new genuine Honda parts.

For used parts, I shop at Beaver's Car Salvage and LKQ Parts (both offer shipping). if you're into scavenging parts yourself, LKQ provides 'pick-you-part' salvage yards around the country.

Always use genuine Honda parts!