I am Archivist of Musical Box Society G.B.  I have compiled a catalog
of Aeolian 176 note Duo-Art pipe organ rolls made circa 1910 to 1931
for self-playing and self-registering pipe organs used in hundreds of
churches in USA & UK.

According to my list, which is only missing a few titles from 600 made
(possibly never issued), your organist forebear did not compose or
record a roll for this system or the Aeolian 116-, 58- or 46-note organ
rolls.

You might be lucky with other USA made systems such as Kimball, Estey,
etc., but surely it does not matter too much if you are using MIDI
about having an 'organ' arrangement.  Could you not use a piano Duo-Art
roll and maybe elongate some of the notes to get an organ sound?

I used a pianola pushup piano-playing machine on a church organ locally
to me some years ago for a concert, and that worked very well playing
65-note piano rolls.

Good luck with your search,
Sincerely,

Kevin McElhone