I found a suitable replacement at ACE hardware, should have written down # and length. Bought them just in case but so far I have been really lucky.I absolutely love my M80M, but this... this is GLORIOUS.
Never had an issue with breaking the high E (or any string) on mine.
The other thing you need to watch is that the locking nut (unless it's a different material on the M8M) is made of fairly rubbish cast metal and if you do up the locking screws too tight, you can tear out the threaded part of the nut. Ask me how I know.
I was lucky to get away with finding some longer screws with the same thread that were able to go deep enough to catch the remaining thread in the nut. So yeah, another reason to be careful with that locking nut.
Enjoy the guitar! It's a work of art in its own right.
Not to highjack this thread, but are your saddle screw rusty? Mine are very oxidized. Drives me insane even though it doesn’t matter.