Waterworks, but not sure they get the best reviews.

Any of these manufacturers could have been found by simply Googling "Unlacquered Brass Faucets". Let your client's fingers do the searching for items.

Make sure the client knows that touching unlacquered brass faucets will make her hands smell and maybe even the house. There are articles online about this.

Any of these suppliers will add 2 to 3 times the cost to a standard product. Make sure everyone knows that up front so the sticker shock doesn't delay the project.

I'm guessing that lots of this stuff is imported and the tariffs are going to make prices skyrocket and delivery times become lengthy. There is only one ship from China that has not docked yet, so if the product is not on the shelf and available to ship, don't accept any lead times.

https://oldenglow.com/

REJUVENATION

brassina

California Faucets. But she needs a DESIGNER for all of these details. She cannot buy direct from any of these places.

Both good sources, If you are "providing" You need the local plumbing supply, after she selects........or you make a wholesale account.

Fergusons is an option if near you. Or a higher end Kitchen/Bath showroom.

Do stay in touch with her after the job is done though. She will soon discover how bad it all looks and in a couple of years will be replacing it.

If they choose a very specific, unusual brand with hard to find parts, I would not warranty your work as you normally would. You don't know how well these parts will hold up and you don't want to be on the hook for costly repairs.

I would ask them to find the items they like online and the names of local suppliers. Then they give you the specs, you tell them what all might be involved in making it work. They order the parts and pay for it and have it on site for you to do the work. This is the process I used when I want something that is an unusual item.

Have them look at DeVol taps. I don't know if they are unlaquered but they might have the antique vibe they are going for.

https://www.devolkitchens.com/shop/taps-sinks?srsltid=AfmBOorcg0dP0_D0_P2mouPA6Vg4ktaqecgU9WjtupMrcJzPvk_1BvQ5

As a plumber you likely already know that Britian & Euro pipe threads are different from US threads. That complicates using fixtures not made for the North American market. More complexity, parts, cost.

I have used European fixtures with no huge issue but honestly when I have a client with this much issue I tell them to find the fixtures and I am a designer not a plumber which BTW is not who should be doing the design . I agree with Kendrah

Neither California Faucets, nor Newport Brass will make "issues" . They will have the styles and finishes.

Tell her to go to a good dedicated plumbing SUPPLY and select.

Then tell her to get over herself......lol and all you do is install, and you only warranty your INSTALL....... not the product