Sony KV-2643R composite injection

[freakaftr8]

Looking at that schematic I could inject my video at the base of the video amp and remove the incoming out of circuit, to eliminate interference from the tuner, I could inject the Chroma at pin 13, but may need a .01 cap to drive down the signal as it will probably be to amplified, and maybe 75 ohm to ground, not sure yet, but based on this, I dont want video to go direct to pins 5 and 6, since I will be bypassing sharpness and sync, that's still needed in the circuit, but I may have to come up with a voltage circuit to amplify the composite to the jungle or there will be nothing there to boost the composite signal and it will be dull since i will essentially be cutting out the tuner on board . Does that sound about right?

On the other hand, simple composite input would be easy, I would just dump the composite at the detector off video amp but may still need to amplify voltage there with something like a 2N2222