Please disregard. I've solved my needs. Thanks for all the useful replies

As posted elsewhere, I am planning to build this low-ohm measuring current source.
Only problem, I can't readily get my paws on an LM385-1.2 voltage reference, or any
of it's assorted flavors (LM185/285).

Can anybody here help me? I need at minimum, 2 pieces.

I'm located in the Pacific Northwest, USA (WA state)

 

Digikey, Mouser, Jameco all show stock.

 

https://octopart.com/search?q=LM385-1.2&currency=USD&specs=0

Shouldn't be a problem to get one.

 

A TLV431 could be a replacement.

 

As could an LM4040-1.2

 

What regulates the 9V output from the 555 converter?
As shown, there is no limit as to how high that voltage can go with a small or no load.
You could add a 9V shunt regulator or Zener to absorb any excess.