Some great, great sounding bootlegs from Wardour label were shared, but we don't have the artwork, or we have artwork in very small resolution. We all would be very grateful if someone can scan and share this artwork in high resolution:
Osaka 1982 (Stadium Rock)boot
Tokyo 16 & 17 1981 (Prime Jive) boot
Tokyo 14& 23 1979 (Pride and Joy) boot
Kobe 23 4 1975 (Dressed to Kill) + London Rainbow 31 3 1974 (Majestic Rock)
I don't know if the resolution is enough for you but you can try the cover archive section in a lovely site I found named queenlive.ca. I don't know who is its webmaster but he's done a very good job ;)