Need help identifying industrial 727

This transmission is used in a vehicle that pushes around aircraft and is paired with an old flat head 6. On the side of the housing where 727 is normally stamped it says 844-5. On the rail above the pan on the drivers side the only numbers I can see are 2659 787L. From the face of the housing to the end of the tail shaft it only measures 28” so I know it’s not from a car. I’ve tried looking up the numbers above the pan but I’ve come up empty handed.