Unfortunately the Jaycar XC3720 LED Traffic Light Module is common cathode.
The only 8 pin DIP and no MCUs constraints are making this project far far harder than it needs to be. I strongly recommend getting a small breadboard and using normal DIP ICS of up to 16 pins, and normal wire ended components. If breadboard + Snap-Circuits integration is required, get their snap to male pin jumper pack:
http://cs-sales.net/snsetsc.htmlHere's a 555 + 4017 traffic light circuit that will work with the Jaycar XC3720 LEDs. It implements the full red, red+amber, green, amber and back to red sequence, with realistic timings for each phase. LTspice sim attached.
It could easily be extended for two directions of lights on a full cross-roads junction with a red in both directions phase for the junction to safely clear. It could also be extended so that some phases hold the 555 in reset so a button or sensor pulse on the other 4017 clock pin is required to proceed to the next phase.
I recommend using a CMOS 555 and a 74HC4017 as they are more forgiving of low supply voltage, and the Jaycar LED module is intended for 5V operation, with integrated resistors to suit, so the 6V max supply voltage for 74HC logic isn't a disadvantage. If you were driving higher voltage bulbs, the classic CD4017 would be more suitable.
N.B. if using a CD4017 at a supply voltage above 6V, due to the transistors' reverse Vbe breakdown limits, the paralleled NPN emitter follower OR gating that drives the Red and Amber LEDs should be replaced with diode OR gating driving a single NPN emitter follower transistor for each LED.