SMPS zener value identification

[meisstupid]

I am planning to make 24v 30A (720w) smps to power 2 units of my flyback speaker driver (build cost of the smsp is one-fourths of a ready-made one, and my budget is low).
I found a nice one with SC and OC protection by a youtuber 'Long Technical', here's the link to the video - .
In the diagrams he attached, few values are missing, and i am still a rookie in electronics. Since the output is 24v, i am guessing the zeners are 24v too, but i may be wrong; I have sent an email to the youtuber but he isn't replying .
The zeners and the ntc are my main concern , zeners encircled in green and red colour and ntc toward the extreme left (photo of bare and assembled pcb attached blw), there are 2 poly caps too but i think i will find them out myself.
Any help or suggestion is much appreciated.
Thank you

[wasedadoc]

You already posted https://www.eevblog.com/forum/projects/any-warningssuggestions-before-i-invole-myself-into-making-this-smps-at-home/msg4953481/#msg4953481 where the gist of the replies was to buy a ready made unit.

[Vovk_Z]

Red cuircuited four suspiciously look like a diode bridge but not Zeners.
(It's easier to guess when you have a PCB in your hands).
And two in green near two powerful MOSFETS look like they are gate protection Zeners, so they could be 15-16-18 VDC rated.

[meisstupid]

sadly, the budget is constraining me(around 20usd short)

[ArdWar]

All diodes are actual rectifying diode. The one near FETs are gate turn off control, the one near 358 are rectifying signal from the current transformer (yes, I'm just as confused). Left cap is part of HV snubber circuit. NTC should be quite beefy low resistance one since it going to bear the entire input current without relay bypass.

This is at the core a fairly basic SG3525-based half bridge SMPS, albeit with some questionable design and routing decision. For example you should treat the auxiliary 15v supply and the whole 555/358 circuitry as primary side.

I mean, what kind of PSU design need completely separate external power supply to work...

[MathWizard]

Would the diodes near the 555 and 358 be for making some PWM drive with those chips ? So just some 1N4148's ?