Your archive contains separate downloads for the ZX Spectrum and the ZX Spectrum 128. These are clearly not the same because the code is different between the two, yet I can find no functional difference between them. There isn't any AY-3-8912 sound in the 128K version, which would be one reason to have two versions. Also, both versions work equally well on 48K Spectrums (even the supposed 128K version – which is actually smaller than the 48K version).
Could you therefore please explain what the difference is between these two versions? Thanks!