By the end of 1983, I owned a Commodore 64 and wrote a basic word processor in 68000 assembly language
No 6510 (essentially a 6502 plus some extra integrated functionality). 68000 assembly would be far less impressive as it was close to the pinnacle of user-friendly CISC microprocessor instruction sets. (After that ISA development went RISC or stalled.) Almost a high level language by comparison.
Correct. Its been a while (22 years)
The Atari ST was 68000.