Does some1 knows if/where you can see how many stuff you actually need to make for example a Dartgun,because the Workbench only say`s what items you still need to collect,But NOT how many of this items,or ist alway`s 1 ?

I know in NV you might need more then 1 of the same item-like 2 Pilotlight 5 scrapmetal etc.

The only item you need multiples of are Caps for the Bottle Cap Mine (10 are needed), everything else is one of each part.

However, you may want to collect 3 of each part so you can make each weapon again as you upgrade the schematics. You get a better conditioned weapon that way. How much better each iteration is I do not know, I never paid that close of attention to it.