I've found three completely unrelated (except for being in West Virginia) locations where a Federal Signal siren with horns (STH-10 or XT22) has a cone hood (like that of the Models 2, 5, 7) on top of it.
Here are the three I've seen:
Slanesville, WV https://goo.gl/maps/sDBeEKiWB9NDQkvE8
Kingwood, WV https://goo.gl/maps/gUepwiMqR1yoXJ8h6
Aurora-Terra Alta, WV https://goo.gl/maps/4Yz1vuV2hwVCtDo96
I was wondering if this was a somewhat common modification and if any of you have seen this elsewhere.