For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Full ASD 3S155 EFI + OS should be around 2.7GiB, it should work on all 820-3115. Download from the usual Russian torrent.
(boards with Mojave BootROM update may not boot ASD EFI but ASD OS will still work)
You can also use MRI 64-bit.