'67 vert hidden stereo install ??s

Hi all,
New member here with a presumably simple question for anyone with experience. I however am a novice at stereo installs.

I bought the Custom Autosounds hidden stereo receiver for my '67 'vert. but am having trouble getting power to it.

First question is, which of the two wires on the factory harness is ACC power, and which is constant 12 volt?

Second question: Can I/how do I connect the wires from the new receiver to the stock harness? It doesn't seem to be a simple plug and play since one of the female connectors is larger than the other, and both the mail and constant power wires on the new receiver are the same size.

I'm sure someone here has done this install before so any help is appreciated. Also interested in hearing where others have mounted the receiver. I was thinking inside the console behind the roll-up door, but unsure how to mount without drilling holes in the console itself.

That might work...if I knew what i was doing. I doubt I'll be adding any other accesories, so this may be overkill for me. But I don't want to cut into the factory wiring either.

For anyone who has installed an aftermarket radio, what source of constant power did you use.

Also, does anyone happed to have the harness from their old radio, or have an old radio with wires intact?