Almost anything can be done, but at what price and what is the real market for such devices? Last night one of the original members of our weekly train group came by (he's moved out of the immediate area and can't always get here). This person had his own signal business for over 10 years and made some early signals for Terry Christopher as a sub contractor. We were discussing this very subject and his conclusion was that: you need a very large, almost club sized, layout for this type of block signaling to work, AND, our observation is that most 3 rail operators seem to be quite contented with reasonably good looking signals that light and change colors when a train passes. The market for prototypical signaling is all but nonexistent in his opinion.
On another subject, i have found We Honest to be a very reliable supplier of inexpensive products. Their signal controllers are really nice and if you don't want to buy 5 just to try them, search their catalog carefully - just bought 2 for about $23 shipped. Also I have been trying to get them to make their round target signal heads in the most common PRR style (7 lights all amber) so far to no avail.
