As far as I know, mines were always just around 5-10 light years away from the intended destination - have you made bigger misjumps?
I cant recall how big my mis-jump was, but long ago I was fruitlessly searching for the fabled "secret ship" in Frontier Elite 2.
Its a myth, that even David himself perpetuated.
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Which is of course a great way to get people playing your game a lot!
You couldn't do it in these days of the internet though, as you can be sure every single system will have been scoured and reported on within a week of release.
You can't reach any edge of the galaxy in Frontier anyway, not without a hacked ship that is.
Your drive will fail due lack of maintenance before that.
Have you tried with Turner's Quest or the Thargoid ship?
How would you know in which direction to point your ship though?