Precision voltage regulator

Hi,
I'm a newbie looking to re-engineer some old Pcb's. There's a obsolete Precision voltage regulator Zn404 or Zn458 which are difficult and expensive to get hold of now. I was wondering if anyone has any suggestions on any potential circuit solutions? It's 2.45volts so it might be substandard?
Thanks

A TL431 is a common, similar shunt regulator with a 2.5V internal reference.
If you actually need 2.45V, you could use a 2-resistor voltage divider to drop the voltage.

The TL431 with no resistors is 2.50 volts. There are different versions 1% 2% maybe 0.5%. So you misted the 2.45 by 0.05. Maybe that is close enough.

The TLV431 is just like the TL431 but with a lower internal reference voltage of 1.24 V. So with two resistors it can make a precision voltage from that up to 6 Volts.

https://www.ti.com/lit/ds/symlink/tlv431.pdf