BrentD;
As I said I have no experience with pheasants, late or otherwise. I had just assumed that most late season wild pheasants would be longer shots. thus my assumption that most early American 20 gauges would no truly be suited for the job.
the Lefever is the particular favorite of mine in American doubles. That said though, I have never owned one smaller than a 16. While there are others out there most 2o gauge Lefevers one finds will be DS grade with steel barrels. If you can find one of these it should serve your purpose well. Personally I would have no qualms with using it with regular "High Brass" 1 ounce loads but would not Magnumize it.
The Lefever is certainly a far better looking gun than a Flues & also has a stronger frame. The Flues & 20 gauge in particular, has a reputation of cracking the frame when used with the heavier, even non-Magnum, loads. In fact I am quite certain they earned this reputation after the introduction of the 2 3/4DE-1oz loads back in the 1920's prior to magnum loads being available in the gauge. The NID was introduced to correct this problem with the newer heavier loaded shells then available.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra