I have also been try to build some signals or at least develop a technique to build some, here are a couple of test photos
I was having trouble with building consistent targets, so I got inspired by another modeler that is using 3D printing so here are by results for the targets
I have a number of request for the LED I used/shown above, so here the link
http://www.miniatronics.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=6_1
More to come....