If anyone cares, these are some games we've been looking for, without success. It's not a huge list, and frankly some aren't really that rare either. But others are really rare...
1977 Zaccaria Aerobatics EM pinball
1978 Zaccaria Queen's Castle EM pinball
1978 Zaccaria Ski Jump EM pinball
1977 Zaccaria Nautilus EM pinball
1976 Zaccaria Combat EM pinball
1977 Zaccaria Supersonic EM pinball
1986 Zaccaria/Tecnoplay Scramble pinball
1987 Zaccaria/Tecnoplay X Force pinball
1987 Zaccaria Spooky pinball
1968 Bally Joker EM pinball
1967 Bally Rocket III EM pinball
1960s reverse wedgehead Williams
1977 Sonic Butterfly EM pinball
1977 Sonic Joker's Wild EM pinball
1978 Sonic Birdman EM pinball
1978 Sonic Jai Alai EM pinball
1985 Sonic Odin Deluxe EM pinball
1980 Hankin Empire Strikes Back pinball
1980 Hankin Shark pinball
1989 Dataeast Playboy 35th Anniversary pinball
1998 Sega Godzilla pinball
1989 Gottlieb/Premier Lights Camera Action pinball
1991 Gottlieb/Premier Cactus Jack pinball
1982 Bally Mr & Mrs Pacman pinball
1987 Bally Dungeons & Dragons pinball
1982 Williams Defender pinball
1982 Williams Cosmic Gunfight pinball