@82mhz
You can try using Bloat FE: https://git.freesoftwareextremist.com/bloat/
Not sure if Go is capable of producing a binary that would run in XP though, but you can always host it elsewhere and use MyPal browser to access it: https://github.com/Feodor2/Mypal68
There was a fork of it that worked in w2k too, but I can't recall its name…🤔
@82mhz
Oh, sorry, I didn't quite get the question — do you want something the blends well with hardware/software of the era? I don't think that even default MastoFE stands out that much, look at what I did here: https://social.librem.one/@m0xee/109225441071185098
Problem is — it might not work in those browsers… 😅
You know what? My suggestion still holds, Bloat might look even more authentic as it's basic HTML with minimal JS.