Have spent the last couple of hours trying to lock my bootloader and get back to stock.
I followed instructions, locked the bootloader, went from S-Off to S-On and as I ran the RUU file, I realised it was the incorrect one.
My understanding is that now that I have locked the bootloader, if I try and boot the device, it would bric as it has the previous custom firmware still running?
I have found out that my HBOOT version is 1.29.401.13 and after doing some research, older threads suggest there is not an RUU file available for this. I am quite worried now as my phone is in recovery mode at the moment and the only way I can see (from a different thread from June 2013) is to unlock the bootloader again, install a different stock rom, lock it again and then finally use the 1.29.401.16 RUU file. This seems ridiculously long, however if needs to be done, I will do so.
I stumbled across a "Guru Reset M7 1.29.401.13" tool, however I am not fully clear about how this will work - if it is even used for the same purpose?
If anybody has information or advice on how I should proceed, it would be extremely appreciated as I have a beautiful piece of metal sitting here uselessly. -_-
Many thanks to all who reply!