Yeah. You can forget the .deb packages. They need dependencies and c libraries and stuff. After 2-5 years it becomes difficult and then impossible to install. You might be better off with some package format like flatpak. Or maybe better yet: the plain executable. probably with statically linked libraries. I think that should work for quite a while.
There are programs out there that come in a single executable file without requirements. they’re supposed to run from an usb stick and without installation. I think you should try those. they should be pretty self contained.
Other than that… I second the question. Why do you want something like an ancient operating system combined with a brand new browser? The OS will have hundreds of security issues. And in case someone does something like plug in a recent usb stick to save some files, it won’t recognize the format because exfat or something wasn’t yet invented in 2007.