I'm nearly done with a great thanks to a friend of mine.
The signal is working for the most part.
There is one small bug I'm not able to fix it jet.
But it's also not a really important bug.
Now I'm writing down all the changes and try to make a .patch file.
(Actually two .patch files. One for simutrans engine and one for makeobj)
Jet I don't really know how to make a .patch file.
I lost the source files where I had begun with.
So I've not a good reference point anymore and it's a lot of work to find all the changes back.
This will take a bit more time.