Ok no problem. I'm uploading it right now.
The intend of that project was to provide a fixed up spirit engine (version 1.9 not 1.5) that adds - fixes and removes potentially unnecessary features.
We also tried to include the best hl1 assets the community ever came up with in a single and easy to use environment.
Be it npcs such as Barniel, new Zombie variations etc.. All in all nothing spectacular but for the simple mappers that lack coding knowledge it would've been a nice thing as all the new npcs would've been easily select able in the mod.FGD file + their sounds. While you can replace models easily in Spirit having them select able is just a mere Bonus. Not to mention that some had unique AI coding.
The project was abandoned when Solokiller began working on Hl-Enhanced and now SharpLife. Makes me wonder if we ever gonna get something usable. Seeing how he keeps switching and swapping projects or starting from scratch idk. We can only wish him best of luck.
The npcs are usable and the engine contains many play able features. Some old hl1 features were re-enabled especially regarding the movement of the player. Still it was unfinished. Reloading a weapon produces a spark for example that was used for testing various things. The Voltigore explosion effect is not a precise re-creation due to math. But other than that each opfor npc behaves the way it did back in Opposing Force just with better path finding.
If you would fix up the "player visible bugs" you might as well use it and progress from that state in there. The coding conducted by Hammermaps was very clean. So it should be easy for you to comprehend his style. Credits in general will have to be given to the model authors (Romka mostly) and him as main coder naturally.
EDIT: Whoops I provided the wrong link before.
Download: https://drive.google.com/uc?id=1smLdf_iyg0iZ_p4-v9HCCZJj5vgcSyEQ&export=download