At the time, the armour would be mostly mail and a helmet.

If there are other components worn on top of the mail, there is a good chance that they will be cuir bouilli, which is a somewhat mysterious material. We know that it is made from hide, but beyond that the unknowns are whether or not the hide was rawhide, tanned, or half-tanned, and what "bouilli", which can be translated as "boiled" means. Leather makes poor armour, and boiled leather is worse. Rawhide is effective, but boiling weakens it. Cuir bouilli was probably rawhide, possibly boiled to thicken it, or possibly heated more gently (which can thicken it without weakening it as much as boiling), or possibly soaked in hot water to make it easy to shape.

However, cuir boulli components of the armour will not be made by a blacksmith. Another worker could easily make them in the time needed for the mail to be made.

The mail will be component that takes the longest to make. In https://www.reddit.com/r/AskHistorians/comments/3zkgky/how_long_did_it_take_a_skilled_armourer_to_make/ u/WARitter estimates about 1,000 hours to make a mail shirt; leggings, coif, and mittens will approximately double this: 2,000 hours. If the mailmaker works 8 hours per day, 6 day weeks, this will take a little over 40 weeks. As u/WARitter notes, mail was expensive, and the labour cost was a large part of that.

An armour-maker will usually not work alone. If the master works with two apprentices, the apprentices will be able to do some of the work, and much of the work can be done in parallel. Such a team of three could quite plausibly finish the armour in about 15 weeks.