How long would it take to complete all of the old Relic weapons?

[Eldevern]

You will leveling faster than you will get relics weapons finished. It still takes at least a few months. If I can risk an advice, if it is mostly for glamour, just do it when you are in mood to do so without really thinking about the time it takes.

This said, you can do one in a few weeks if you are really dedicated. What will slow down you the most is if you don't have enough tomes (though you can solve it with roulettes, Eureka and hunts).

You can use it as glamour as soon as you don't destroy it. About the copies you can buy, I'm not sure how it works. For Eureka, I know the last step needs BA down to be considered as completed.