Well, the Magic Tour rehearsal is featured in the Wembley 1986 DVD, so you would have to buy the DVD, and then convert the audio to FLAC or WAV, as you prefer. Those wouldn't be truly lossless files, but that's what QPL gave us.
And for the Live Aid rehearsal, search the post where Chief Mouse announces that video, download the video and convert the audio to FLAC. It might be lossless, depending on the quality of the video's audio.
Pittrek's choice would be the wisest one, in my opinion, if you just want to listen to the audio and don't really care for the video.