If you absolutely have to have a LH safety, would it make more sense to modify a flip safety in the same manner as AR ambidextrous safeties are made? This would involve somehow attaching a second lever to the left side of the safety. If you must have a LH push safety, it would probably have to be redesigned to relocate the slot that blocks the trigger bar. I would question the reliability of either approach, not actually having done it.
BTW, a left handed rotary safety was tested by the Army but never adopted.