Lunar: The Silver Star Working Designs T-127015 December 1993 US
Lunar: Silver Star Game Arts T-45014 06/26/92 JP
Hmm no eu version made
Action replay my of let you boot another region or simular CD, not sure what CD's came out for the Mega CD, I missed out on that console myself
Edit* think there ware a CDX version of Action Replay, if it's anything like the other action replays of the time and for a few years after it should let you boot other regions through it
http://www.amazon.co.uk/Pro-CDX-adap.../dp/B002PI7ZR6
Just to look at not saying rush out and buy it, there out of stock anyway, but I'm sure you will be able to find it, either on amazon (diff seller obviously) or ebay or maybe a local game trade shop like grainger games or the like
There is also a CD+Plus and CD Key, P.S. all of these are carts not CD's but all enable imports (Not sure if this would help with copied imports)
EDIT* lol ebay have a CD-X for about £40, meh buy a controller for your PC or a second hand Xbox original (hack it) and emulate the game, that game is well worth playing though, personly I like that version more than later versions, I can't pin point it exactly but even though later versions are greater in file size and have very nice graphical updates and longer game play I think the old Mega CD version had a good balence and keeps you wanting more until the game has been completed, yet later versions I have still yet to complete, P.S. the game does emulate perfectly by the way, atleast through Gens and Kega Fusion, yet to play this on my Xbox.