Tomorrow I am buying a newer Flying Scot 5339 in the hopes of upsetting our rivals at the Asheville Sailing Club.  Our trusty 3440 has been maintained and repaired to the best of my abilities, we find the other Scots in our fleet (7 regulars!) slip by 3440 regularly, both in pointing, and in speed.  I have done everything I could think of, but assign the slower speed to the fine shallow spider cracks in the hull, that make a somewhat rough surface.  I have sanded the worst offenders, removed some "house paint" on the keel, and things like that, but she is still slow.
I am going to sell 3440 with full disclosure about her relative performance.  She is a fully race rigged, with lots of new essential parts, and would make a great first boat for someone wanting to learn and on a budget.  I hope she can stay at our club, as we have a waiting substantial waiting list for the limited trailer spots at our marina.  That will bring our fleet to 8.
One concern was the centerboard.  I have heard that the mold for the centerboard was "redone" at the factory sometime in the 3000 series, and that my boat was one of those with somewhat "different" profile.   There area various opinions about this story.
I have maintained the centerboard to 1200 grit smoothness, with special attention paid to fairing the leading and trailing edges.  The board looks fantastic.
When I measure the board 24" up from the lower tip, here is what I find:  The chord straight across measures 16.44".  From what I read about centerboards they should be bulged outward 10% to create the shape.  I am thinking that is 5% rise to each side, with the highest point one third of the way across, with the bulge foreward.  The highest point ismeasures correctly one third forward.  That's good. 
But the actual measure across the centerboard surface is just .35" more than the chord.  At 5%, that should have been.83".  Put another way the the actdual surface distance across is only 16.79"  when it should be 17.27"
I don't think there is any data on what the board specified dimension is, but it would help me to know if anyone has looked at this in detail before.  I have enough engineering training to leave all that out of this topic, so as not to bore everyone to tears.
My purpose is to properly disclose this item to the new future owner of 3440.  Any of your comments would be greatly appreciated.
Thanks again to Charlie Buckner who has been a great inspiration to me to sail a Flying Scot.