Recover old Xbox account n gametag

Hello Gaetano, this is Manuela. I'm an Independent Advisor and community user like you, ready to assist with this.
Not a Microsoft employee.

I would like to let you know that, unfortunately, the gamertag assignment is automatic. It is not possible to remove the numbers if the system added them.

Hello Samuel,

Thank you for keeping us updated. Do you remember the gamertag of that old account? It is possible to recover the account as long as the gametag is known. We recommend contacting the
Xbox Support Team with a detailed description of the issue. Once the account has been recovered, we can remove the Facebook account associated with it. Be sure to let us know
the results!

what you can try is this

start up the old xbox and save eveything in the cloud then afther thats done startup the new xbox recover the gametag there and get the saved games back from the cloud

Recover your gametag
on your Xbox

Thx its not a biggie but if i cant combine the 2 accounts then no real point to recovering my old one(jesta151)atm.thx for letting me know n how to retrieve the old one if i decide to.i dont have 2 xboxs or id totally share between the two though.