Learning is figuring a great deal of it out on yer own, following some tutorial is basically just copying.
On the CG version controller there are a couple things ya have to be aware of also.
1. The 555 timer ya use needs to be the CMOS type so it can run off the lower battery voltage the Wireless controller has versus the Wired controller, Rat Shack does have those.
2. The Triggers on the CG version are backwards from the Matrix version. The Triggers on the CG go High (voltage) to fire instead of Low (ground) like the Matrix version.
So as far as making the buttons on the CG R/F ya build the exact same circuit ya did to make the Triggers on the Matrix work, then just wire it up to the buttons on the CG instead of the Triggers of the Matrix and those extra buttons will be you're R/F A and B buttons.
To make the Triggers of the CG R/F, since they work backwards from the Matrix, ya just need to take the output of your 555 and go thru a new button then to the Trigger. It's the same 555 circuit as what ya did before with the Triggers on the Matrix, just minus the Transistor(s) is all.