shakespeare (dramas):
1. Myself have letters of the selfsame tenor.
2. Myself will straight aboard: and to the state
or
emily dickinson:
to wonder what myself will say
i think the reason they did not add 'i' before 'myself' was that myself is an iamb (unstressed/stressed). for instance, in a sonnet, we normally use iambic pentameter (5 iambs) for each line, and such an iamb was necessary in classic poetry for its musical effect.
true 語堂 used it too (the 4th line):
http://web.wenxuecity.com/BBSView.php?SubID=mysj&MsgID=59340
but normally in writing, i think we should not use this way.
another popular usage (in my opinion, not grammatically correct either) is this:
she and myself will go there
(it should be: she and i will go there)
in fact, shakespeare had such a sentence also:
Lysander and myself will fly this place.
if you look at all the sentences, after myself, there is a word 'will' or 'have' after 'myself'.
what if you say:
myself am fine
myself is fine
or
myself are fine
none sounds good, right?
therefore i would prefer to add 'i' before 'myself'.