Like you said yourself, the INT should be valid, you could certainly accumulate a lot more miles out of it if you wish, depends ofcourse where you want go...

If you do not find any other use for your last segment, you can always fly HEL-LHR-JFK etc to enjoy better J cabin as you have only 3 segments in Europe . Finnair won't have sleeper seats on their MD11s until later this year/early next year...but then again you AA members do not like to cross the pond on BA metal...