Do you mean casting these kinds of parts out of metal? To do that would require some pretty specialized methods involving heat, casting alloy and molds and most here, including myself, would rather buy those upgrades than make them.

Have you seen the metal wares available from Backyard Armor for instance?

http://www.backyardarmor.com/Elite_A...tail_Parts.htm

I suppose however, that you could make some of these things out of sheet metal, like sheet brass, steel or aluminum. It is possible.
Brass or copper is very soft and could be formed into a shovel with the right amont of finesse. I could do it but I'm not sure I could teach you.

Let us know what precisely you are interested in and for which tank and we could take it from there...

-Harq