The double post is due to the site not reacting without hitting the "post reply" button multiple times.
I have a few guides & various contraptions for sharpening. I about always just use a loose file with a handle, freestyle. If the chain is off the saw I put it in my vise, 2 teeth at a time. I’m not saying I’m a ‘pro’, but do get-R-done.
Stihl 3/8P (picco)uses 5/32, but you are correct, Normal 3/8" takes 7/32" file although Stihl uses 13/64" and their file guide just like the OP will fit the same size file.
