Front brake master cylinders. New ones?

On my 78 KZ1000, the plastic brake fluid resovoir is yellowed and chalky. I'm a stickler for details and after I restore the bike, I want everything to look new. Is the resovoir still available new? Is there another set up to go with from another bike that has the round plastic resovoir? Year, Make, Model??? I do like the smaller round ones that I see on newer bikes. My rear one is weathered too so what to do about that one too?

Dimecitycycles.com might have something you can use....

No eBay APP ID and/or Cert ID defined in Kunena configurationYou can't find new trapezoid master cylinder parts.
Don't waste your money on a used one from ebay. All the bore are pitted.
I re-built 4 last year. I bored old pitted 1/2" cyl. to 5/8" Then paid $50 bucks for 5/8" Kawasaki kits from Jeff. Saunders. I glass beaded them. I used 2 and sold 2 on ebay. I did not make anything on them

Here you go $100 to your door in the USA.
Rick Brett, the 2 stroke guru from England. Sell's out of Michigan also.
Bolt on and add fluid then bleed.
Aftermarket knock off's.
Why are there so many watchers?????
Want one, you'll have to buy one! Jeff @ Z1ent sells them also