The OG game web page as a mini game that gives gundams away for 45 Astros. A got a BS grade GP-02A Physalis with has different specs that the one that is already there. I am trying to add that other version.
As you work on a suit it levels up right? First you get soldier (Special) then Ace (Skill 1) then Veteran (Skill 2) (possibly reversed but never mind). After unlocking skill 2 if you fill the unit's EXP bar again it becomes level Custom 1. It's that easy!