Trying to adapt a V8 dash harness to a 6

[wh23g3g]

I'm trying to adapt a 65 V200 8 Cylinder underdash harness to my 65 V200 6 Cylinder dash. Everything is pretty much the same. Some of the wires are different colors and I hope they're all wired to the same circuits. I added a few wires that weren't on the 8 Cylinder harness. One for the transmission shifter indicator and one for the backup lamp switch. However, I'm trying to figure out how to wire in the correct AM radio. I see how to do wire the speaker in. It just comes off the radio itself. But plugging in the power wires to the fuse box is a little more confusing. I have the factory 65 Chrysler Valiant repair CD and in the wiring diagram it shows the Orange wire needs to be plugged in with the transmission indicator wire but there's no free blades left on that fuse to plug into. The red wire is easy, it just plugs into the radio feed which has an open blade to be used. How do I plug in the Orange wire since there's no free blades on that fuse? I assume the Orange wire lights up the radio since the other wires on that fuse are wired into the headlight switch. I also have to figure out to repair my hacked up dash where someone before me cut it too wide so now the OEM radio doesn't fit right. It may be hard to get in there and weld on a panel especially since I don't have a template to follow. Hopefully with this harness everything will work the same. It's a real nice harness with nothing being cut or torn, compared to the one I took out that had a meltdown.