In answer to your question, regarding Space Ace and Dragon's Lair.
Both of these units were licensed from Cinematronics and made by Atari (Ireland).
These versions were slightly different to the US models, where extra screens were shown (remember the extra sequence in the Black Knight ending screen?).
Since it was designed on a different system, the LED displays were not shown, but a graphic overlay was used (rather chunky too).
Also there was some "interesting features" inside the game. Dragon's Lair had a cheat feature when you played a 2 player game. You kill off the first person, and finish the game without dying with the second player. This allows the fist player unlimited lives. I had exploited this on rainy days in Blackpool (where I lived)...
The machines are extremely difficult to get, especially ones with 2 player options (lol).
Hope this clears up any forgotten Nostalgia.
lloydcom