Amazing OP!
Is it true that Taito lost the source code to the arcade version so none of the subsequent ports were exact?
Pretty much, yeah--some of the earliest ports did have access to the code (even the European ports, not that they were able to make any sense of it) but by the mid-'90s it had disappeared, apparently.
It was a difficult game to accurately emulate for a long time, too--a lot of the game logic was co-managed by a somewhat uncommon microprocessor that had to be decapped in order for people to figure out what it was doing. I'm not even sure the recent PS4 release got it right.