Unless you have access to a machine shop, making the brass/metal hardware by hand is difficult at best.
I think as time goes by we get lazier and forget how things used to be done. All of the brass parts on a camera can be made with simple hand tools. It's not easy but it's still possible.
One of the best tools at your disposal is ingenuity. Spend some time looking at a problem and see if you can come up with another way of doing it using the tools and materials available to you. For instance, if you see a camera which has most of the front standard parts made from brass you may be put off if your metalworking skills are not up to much but look at a few pictures of cameras and you will find some with most of these parts in wood.
If you're not too good at woodwork joints then have a look in your local hardware shop and see if they have any brackets, catches and fasteners which could be used.
In order to make a working camera in its simplest form, you only need to achieve two things:
1. Get the lens the correct distance away from the film.
2. Keep out any light which is not coming through the lens.
Anything else is an added bonus!
If you don't want to build everything then a good way to start on your first camera is to buy a spring back film holder and build it from that.
Steve.