This is really just a note for anyone with a similar problem I was having during my development of the Holocom electronics.

When trying to burn the Arduino bootloader to the raw ATMEGA 328p device at 3.3v with using an internal clock, I kept getting an error :

avrdude: Device signature = 0x1e150f
avrdude: Expected signature for ATmega328P is 1E 95 0F
 Double check chip, or use -F to override this check.

Searches of the internet revealed nothing but a single other post that mentioned the chip could be broken.
I tried to burn the bootloader to 6 or 7 of the chips I had with the exact same result, so if felt like the chips weren’t the issue.

In the end I found the issue to be that the default bitclock speed was too fast causing a weird read error.

By adding -B5 to the avrdude command, the chip was correctly read and the bootloader burned.

I hope this helps someone.