Firmware password on Mac A1278 Mid 2010 (bypass)

Hi everyone, I'm working on a mac A1278 of 2010 abandoned in italy by an American at a party more than a year ago.
Mac has set the password on the firmware and on each action comes the pin request or the flashing folder with the question mark.
The original disk has been accidentally formatted and I have performing test-disk with advanced analysis for recovery of previous partitions was interrupted after 4 hours at 0.1%, was placed in the drawer as the last alternative.
I have tried another mac (vmware) to install sierra on the new ssd, but the disk does not seem bootable and there seems to be just the preinstallation files.
I tried to create multiple partitions:
1. EFI partition
2. Installing Sierra (with Diskmaker)
3. Sierra pre-installed (from vmware)
4. empty partition
I have put the bootloader on the pre-installed sierra partition (3) with refit.
I installed the refind bootloader on the /EFI/BOOT/ hidden partition
I renamed the refit.efi file in bootx64.efi (after running the install script) is the procedure correct?
I also have to try to rename it in bootia32.efi because I think the 2010 mac is only 64bit compatible, but the bootloader is still 32 bit.

Before the original disk has been corrupted the Mac OS loaded correctly. (Something else made this mistake)
I think changing the bootloader to bypass the firmware password is a working idea. But from your guides I read that the boot looks for the EFI file in this /system/library/coreservices/boot.efi path and not in the hidden EFI partition, is it correct? (but the new ssd is empty)

Option + command + p + r at startup have no effect.
Flashing the chip is not an alternative I want to go through.

Any suggestions are welcome.
Thank you

Ps: excuse my horror English.

Not even a tip? I do not know what to do.
thank you

I don't think you're going to be able to remove the pin code by messing with the hard drive.
Have a look in the other threads on how to go through the pin codes via a teensy micro controller or flash the SPI ROM with a raspberry PI.