...all strings have one sharp and the final chord seems to contain only e's and b naturals....the Public Domain version which showed the Clarinets in A, not B Flat...
Sounds as though your piece ends in e minor, which goes along with the single sharp. If the A Clarinets are sounding "A" when they read a "C" -- that means you write for them at a minor third above. So the A clarinets would have a key signature of Bb (two flats)..and be reading in the key of g minor, but you would
hear them a third below, in e minor. [So, in your original question, the original score was correct, the confusion was over it being written for A clarinets.]
I would like to add something regarding French horns: they are typically scored without any key signature, and accidentals simply inserted where necessary. The relationship of how they are notated has also changed. Whereas in the nineteenth century, F horn parts were written so they would sound a fourth above, current practice is to score them so they sound a fifth below. This does obscure the current discussion regarding transposing instruments, but at the same time is part of the difficulty in understanding the issue at hand.
French horns have evolved, and now have keys, but players used to have to insert different pipes during the historical period when they could only play the natural harmonics. So the composer had to know what was possible. Horns in F sound a fourth above,
(or a fifth below), so the horn parts should be reading a fourth below,
(or a fifth above), in b minor, in order to sound in tune with the non-transposing instruments written in e minor. The horn part would have two sharps. [In your original question, if the correct key signature for the "horns" truly was three sharps, then the original score was written for horns in Bb. They would be reading in f# minor, but you would be hearing them play in e minor. Is it possible the original part was for Bb horn?
However, any key signature for the F horns would be a divergence from the practice noted on the Vienna web link below.]
The Vienna Symphonic Library web site has some interesting facts on orchestral instruments. Here is a link to good information on notating for French horn:
http://www.vsl.co.at/en/70/3139/3141/3142/5412.vsl
Reading full scores can be like deciphering a crossword puzzle. I wish the current implementation of Logic had been available during my college days.
I have found transposition errors in public domain MIDI scores. It is pretty obvious upon playback, when Mozart sounds like Penderecki...