And here's the original assembler: https://github.com/fesh0r/newkind
Various old/remade/ported versions here.
And the original programmer has heaps of stuff about/for it here, including source code, manual, and even a Text Adventure version:
"Elite" was originally written in 1984 by myself (Ian Bell) and David Braben for the BBC Microcomputer. It has since been converted to many platforms. The best conversions were for the Nintendo Entertainment System and the Acorn Archimedes.