Respawn the original ender dragon on server

On my server, we've lost the dragon egg so are trying to get it back using as little cheating as possible. Because of that, we're now looking in to ways to reset the dragon counter and make the original dragon appear again. We've had no luck so far though, so I was wondering whether someone here could help. The other post on the matter: Respawn the Ender Dragon has been of no use.

So we're looking to do the following on a server:

• Summon an ender dragon
• Have this dragon drop an egg without changing loot tables (NBT editing is fine though)
• Keep the end intact

Having it drop the original 12k xp is fine.

Ideally, we'd do this using a command from the console, but other methods are acceptable. Hope you can help!

I don't think this is possible with commands, but if you have access to the server files you do it with a little bit of NBT editing (with e.g. NBT Explorer):

1. First you need to break all portal blocks - both in the the exit portal and on all end gateways on the main island. You can do this in creative. Unfortunately there is no way around that - if there is a single portal entity within 128 blocks from the center, the game will know you have already beaten the dragon.
2. (optional) If you want to have the fight with the end crystals healing the dragon, respawn the dragon manually and wait for the spawn sequence to complete and then leave the game. If you don't care, just skip this step.
3. Then, (stop the server) with the NBT editor delete level.dat/Data/DimensionData/1/DragonFight (save and re-start the server):

Then, as soon as one enters The End the dragon will appear and the game will consider it to be the original dragon. When it is killed, the game will put a dragon egg on the portal. Also the dragon will drop the XP of the first kill (12000).