Advice on A1534 Retina 12" please

Hi all.
I purchase a MacBook retina 2015 12" on Gumtree (UK Craigslist) for my daughters Christmas present.
Model A1534 - EMC 2746

Not knowing a lot about mac's, the fella that sold me it said I would need to do a fresh install of OS X, and showed me what buttons to press.

So I get home and press Command+R.
Was meet with an option screen and selected Fresh reinstall.
I was then prompted to connect to wifi, so I put my wifi password in and the Mac rebooted to a black screen where the word ALERT flashed a few times and then a padlock with text box appeared.
If I switch off and back on, I get a flashing folder with a question mark inside.

After a bit of research on the forum, I've come to the conclusion that the MAC is EFI password locked and maybe iCloud locked?

Can anyone help answer some of my questions?

1. Will the EFIDL remove the lock from this model?
2. When will it be back in stock?
3. Are there any U.K. Distributors?
4. Once and if the lock can be removed, can I re-instal OS X from the recovery option ?

I'm quite desperate to get this thing working, as it's a xmas gift and I'll put my hand to anything.
I have a pie, wellon programmer and a bit of patience but no knowledge on this field.

Thanks

the flashing [?] screen means that the MacBook has been remote erased
that indicates both iCloud and EFI lock. the EFI lock is invoked by the iCloud lock

the efidL is still somewhat experimental with a1534 models, but it can and has been done
you'll just have to watch the store, they come into stock and sell out quickly
there are no other (authorized) distributors

once the lock is removed, it is recommended to install from USB media not recovery partition

there are a few threads currently of people working on 12" MacBooks, and even on the SUCCESSFUL FLASH ENVIRONMENT thread there is a success video performed with the raspberry pi.

some techniques require more technical skill than others, and are accompanied by greater risk.

Thank you for your detailed reply.
If I successful remove the lock and re-install OS X, can the Mac go online or will it get locked again ?
Thanks

the iCloud lock (findmymac, etc) is stored in the EFI rom.
when the EFI lock is removed, you can clear the iCloud data from the EFI rom
then a fresh install of OS X from USB install (internet restore and system restore will be linked to old iCloud)

clean EFI + new OS X + your iCloud account = YOUR mac now

Thanks again.
This now makes much more sense to me.
What is the benefit of changing the serial number ?
Do I need to do this.

there's no real benefit to changing the serial number unless you want to resell it and are afraid that somebody might identify the serial number as their own.

apple does NOT record, report, or track anything whatsoever. the extent of their involvement is providing the findmymac service and iCloud lock. any action on their part could be misused and leave them in an actionable position.

as long as you've cleared the iCloud info from the EFI rom, and have a new OS X install, the previous (rightful? lol) owner can no longer track, lock, etc.

Thank you once again.
I'll dig out my old programmer and see what I can do.
I take it, once efi is removed and OS X reinstalled, iMessage, FaceTime and AppStore will work with my existing details.

You are correct. Logging in with your Apple account will write your details into the SPI ROM. If you can't get a clip, you'll have to program by soldering wires onto the board. I would have borrowed you a clip, but I only have the V4.0.2. Check out the successful flash with this board as directed. Good luck.

Yes and please do let us know how you get on!