5mm Red LED Flashers

[chuff_n_puff]

I need some suggestions from someone with electronic savvy. I have several flashing 5mm red LEDs in tops of water towers and coal tipples. I needed to replace one that quit and install some Fred lights on some caboose. Now I can't even find a flashing LED online or at hobby shop that will flash. I've tried all ranges of resistors. I have been trying the clear LEDs, as I can't find the diffused. Would that make the difference? It shouldn't, if I use the right resistor. I use the formula, supplied power - bulb voltage / .02 and start out 200 ohms above that. I  also have some bridge rectifiers I was going to use on the DCC rail power for Fred lights, but I can't get past the 12vdc scenery units. Can anybody help me?

[NelsOn-30]

chuff

Try http://www.modeltrainsoftware.com/dcflasher.html

They seem to have what you are looking for, both 3 & 5mm