Yeah, the original encrypted game images are useless without the keys. For their newer hardware's game images, Sega lets you download them straight from the net, so I'm not sure why they would care for Lindbergh ones.
Of course the admin team here has the final word and I'm not here to contest that.
I mostly agree with you @nem and I think that it wouldn't hurt having them posted here. However we don't want:
a) being associated with a "arcade download" site, we are arcade projects site.
b) It's not our IP. I'm sure Sega won't be happy. Probably they don't care, but better safe than sorry.