Now if you have made them, you should know all by heart. So it would not be difficult to design them with some Cad. I believe this is the preferable option.

Ok, you can scan them but the out put will be STL. So google now "how to convert STL to solid" , you see, not so simple and much time consuming.

Plus you will surely design new in the future. So the experience in drawing is needed. In short if i was you , i would draw them from scratch in some good parametric design capable CAD. The more you draw the faster you do it. And you will need the skill, for the first client that comes and wants something complicated.