Try Liz's Hardware in Los Angeles. I have gotten vintage hardware.

If you post a picture, perhaps there can be some further suggestions based on the specific design.

Any lighting show room thats worth a crap, aka a mom and pop will have parts, and most can order from the Luminance (formerly ADR) parts book they have any and every part.

https://www.luminancebrands.com/adl/

Tehre are many many sites on line that sell chandeliere parts, but I don't see any with Delft parts....your best bet will be antiques oriented site that saves broken Delft lighting for the parts.
I suspect people preciously replying have no idea what a Delft Chandeliere is.

The color canopy doesn't need to be Delft, if probably would be brass or what ever other metal is on the fixture.

Liz's Hardware specializes in vintage hardware and has an amazing inventory. They have a website and you can contact them via email to see if they have something that can be used.

I have a vintage chandelier that used to be a gaslight (it was wired for electricity in the 1950's) and they were able to supply me with the screws I needed for the globes. I also got my vintage door knobs from them.

Here's a thread on a Delft chandelier - is that the kind of canopy you need? If necessary you could probably replace with a vintage brass or whatever metal matches the rest of the metal and it would work.

Delft Chandelier