Hi,
I mad a point contact diode back a long time ago using iron oxide and a sharp needle. Many people did this actually and it's not hard to do but takes a little patience to get going.
I never got around to doing it with a transistor though.
People make all sorts of home made devices like this, including solar cells. I would not bet on how good they are though, but it may be interesting anyway just to see how it works first hand.
It's too bad that many experiments done today have to be in a lab with expensive equipment and a good budget to be able to afford precise machining and whatever is needed to construct good projects. The LHC being the best example.