Hi.
Can somebody please tell me where can I get Sfall for Fallout 1 nowadays?
And which patches are there to update the original game (no mods) except those already in the GOG installation?

I don't know about the standalone version of sfall for Fallout 1.
All i can point is that i completed several years ago the gog version of Fallout 1 by using Fallout Fixt , that integrate a lot of fixes and improvement and various optional additions , and features Sfall for Fallout 1 inside of it.
https://www.nma-fallout.com/resources/fallout-fixt-full-all-fixes-and-mods.8/

Apparently people now use Fallout Et Tu that runs Fallout 1 in the Fallout 2 engine, tough it requires you to have Fallout 2 installed, never tried it myself so i don't know if nowadays it's a better solution than good old Fallout Fixt
https://www.nma-fallout.com/threads/fallout-et-tu-release-v1-10.218045/

I use Fallout1in2 (which I believe is Et Tu, though need confirmation since its been a while) and it works great on Win7 (not sure Win10 or 11).

It's really awesome to playing FO1 in the FO2 engine. FO1 feels like the same story, but with all the perks of FO2 QoL improvements (like FO2 inventory and companion combat options to name a couple). I can't play w/o it now and I loved both games, so it's a win-win. :)

And yeah, I think it has all of fixes that Fixt has and even more fixes added on top I think. I'd have to go look at the notes, but I believe so.
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You just convinced me to try that fallout 1in2 for my next Fallout 1 re-run ;)

You won't regret it, but do come back and let us know how it turned out if you can. Might be handy for future GOGers trying to replay it. :)
. Oh, if for some reason you get stuck during installation, let me know. I should be able to help, since I took notes. Though if my memory is accurate, I don't recall having any install issues.
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Downloaded the latest version of Fallout1in2
https://github.com/rotators/Fo1in2/releases/latest/download/Fallout1in2.zip

and fortunately the instructions were simple enough and everything went smoothly
https://github.com/rotators/Fo1in2/blob/master/Fallout2/Fallout1in2/README.md#mod-installation

After launching the game once, i left and set it to windowed mode instead of fullscreen.
In the Fallout1in2 folder i edited :
f2_res.ini with WINDOWED=1
ddraw.ini with Mode=5

Will toy around with settings more later, but so far everything is in order , time to get another Fallout run :)