It's OK, I've figured out how to dissemble the Z80/SNApshot files (and TAP files) into pure ZX assembly language.
It's easy enough to do (see previous link from my last post) - it's understanding the assembler that (at the moment) is a bit intimidating; mostly I am used to high-level languages. The more you pore through these things though, the more they make sense. For example I've already found the (seemingly) random string used to generate the planet names, which is a good enough start as any!
The previous link can be used to dissemble any ZX snapshot type.
WRT to Elite however, I'll probably post to a moderator or general support, just to make sure I am not treading on any 16-bit toes
If it is permissible, I might offer to update the original 48K version with comments for all the routines in order to be able to better tackle the Legends version - then if FD want to they can release the ZX version assembler 'sources' to all and sundry (unlikely they'd want to, however!)