Just wondering why there isn't rules covering Crafting Attachments. In (EoE) Special Modifications book you can craft weapons, droids, gadgets and cybernetics. But they don't cover attachments. Has anyone come up with their own house rules for this? I don't think it would be difficult, just wanted to see other's ideals for it.

Probably because you can't "craft" all kinds of attachments as they already are just "materials" added to equipment, like Superior, Cortosis or Weighted Head. Other stuff like Energy Cells for Blasters are something I would call part of the materials you have to buy for crafting Droids/Weapons.

There are certain attachments you could craft but it can be hard to come up with templates that are general enough to cover them all.
Additionally, crafting provides further improvements through Advantages and Triumphs, and I'm not sure if giving free modifications through crafting checks would be the right thing.
If you want to do this, your GM could allow it in some cases and base the difficulties for the "templates" on how complicated the attachment seems.