Out of your junkbox you may create your own LM723, with better parameters, when lucky

This is a Sunday's afternoon project for people who like 723 vintage technology.
You may get:
1. lower min operating voltage,
2. more stable and lower noise Vref (here 2.5V),
3. much larger output current,
4. otherwise -> MY723
Here is a schematics which mimics the LM723, with above improvements.
Adjust for your needs, do experiment with different parts and values..
Use at your own risk
