There are 3 versions :
Smecno around 4'15
Hereford slower around 8'50
Before recording, I heard half a dozen versions of the original version (e.g. baroque orchestra) of the sinfonia. They all were very fast (around 3'30-3'40) and with practically not the least slowing until the last five or six measures). It possibly influenced the first Hereford version, which I find a bit "oppressive";
So, I tried something slower and it did not work at all on hereford (as an example, one of these junk takes is at 8'50).
Finally, I tried a more restrained approach on Smecno (around 4'15)
There exist many transcriptions of this piece, by at least Guilmant, Isoir, Saint-Martin, Hebble, Rawsthorne, etc…You can find a fine version of the Guilmant's one here, by Sanden : http://www.contrebombarde.com/concerthall/music/15174