Guys,
There are many ways to reproduce things, create parts and so on.. You guys should check out the model making threads on the
http://www.therpf.com/ that is movie prop building message board I'm part of, there is a lot of good info, a lot of great do's and dont's and the ethics on reproducing certain things.
Well onto making parts. I too want to reproduce some pedals blocks. There are a few ways of going about this, most all ways require some money.
One way is to find and ask someone that already reproduces them and see if they are thinking about making the parts you want. Maybe create a list of potential customers. Or if you have an original, tell them you will supply the original in exchange for a few sets.
If you want to copy something like a pedal block you will either have to find a really clean NOS piece or have a pattern made.
The pieces posted in the first post look like they can be either fiber glassed or vacuum formed to make copies.
I mainly question casting mold rubber pieces that get a lot of abuse like pedals. I know modern urathanes and rubber are great but still durability is an issue with that particular part.
Zamak part, or Pot metal likelight housings can be copied though making a sand casting.
BTW guys, not many people get rich off of making just some parts. There is a lot work involved.