Hi Lucky.........gosh I thought I was short at 5'4" I ride a 48. I had my bike custom built by Serotta and of course had one of their bike fits. If you have a Serotta dealer in your area they will do a bike fit for you and you can go from there.
You'll find out IF you NEED a custom built or if you can by a frame off the rack so to speak. Sounds like you've tried all the tweeking of seat and ect....I can only add that there is IMHO nothing sweeter than the feel of steel!
I wish you luck and post back what you've decided.
Kate
Life is like a 10 speed bike, we all have gears we never use.
Charles Schultz
"The bicycle is just as good company as most husbands and, when it gets old and shabby, a woman can dispose of it and get a new one without shocking the entire community." — Ann Strong, Minneapolis Tribune, 1895