Andante Cantabile (4th Symphony)

I'll probably have my account closed down, my uploads deleted and all trace of my passing expunged from CB for uttering the heresy, but, on the whole I'm not much of a fan of Widor's music. I find I don't engage with it particularly (and that includes THE toccata).
However, this movement is an absolute delight, even if there is one bar which, as far as I can see is impossible to play as written by anyone, like me, who has his fingers configured on his hands in the conventional way. (The arpeggio bit near the end, with a long note on a different manual - I can't imagine any contortions of thumbing up, down or around to achieve this. Any guidance would be appreciated.)
I don't yet own a suitable French sample set, so, until then, I'm having to manage with Hereford.