June 11 2020 Postal III Beta Leak. Need help getting the dev test maps working

[Crocodillian_From_XEN]

The Postal II leak come with a lot of content from Valve games... But none of the games work straight out of the box. So I was curious on how to get the Half Life 2 Content from this leak working ... I've tried creating a .bat file that launches HL2 from the leak folder, but the game always crashes before it can load into any map.

I used the command console to find out what the version was, and this was the result:
Protocol version 7
Exe version 1.0.0.0 (hl2)
Exe build: 13:27:28 Aug 10 2007 (3198)

There are 9 dev test masp I want to play through (as seen in the image I attached), But trying to load the maps (and the HL2 folder from the leak) through ModLauncher and Leaknet didn't work, and launching the maps from the first release of Half Life 2 didn't work as well (yes I know that's dumb, but I was desperate). The only thing that I think could wok was getting the dev test maps to load on Half Life 2 Build 3224 because the build dates of those builds are before, and after the the hl2 beta version of the leak. But I can't find any downloads to either of those versions. The only download I could find is this archive.org archive of the orange box from 2007 LINK , but i'm 100% sure the install file will just connect to steam and try to force me to install the game from there. So that's not a good way to obtain HL2 Build 3224.

When I tried to play the dev test maps in Leaknet, the game said the maps where made in Protocol 20, while the game itself was protocol 18? What dose that mean?

So how can I get Half Life 2 Build 3198 working and play these dev test maps? Dose anyone know how?
Any help and advice is thanked in Advance!

[Cvoxalury]

I would decompile them first (using BspSrc) and then open them in Hammer to see if they're worth playing at all. Chances are high they're just Valve's own devtest maps which you can get in the leaked Episodic mappack, and there the devtest maps are mostly HL2's maps like Water Hazard or Anticitizen One with some entity scripts being tested on 'em.

And if it's the same devtest maps, well... then it's easier to just compile them from the mappack for the current engine instead of hunting down protocol 20.

the game said the maps where made in Protocol 20, while the game itself was protocol 18

It means they're compiled for retail engine. Leaknet cannot possibly handle them.