From the accompanying photo, it appears to have been one of the turretless ones modified into an M4 artillery gun tow/ crew and ammo transport vehicle.
From the LA Times article, it would appear as though the M5 was modified and no longer has a turret. Basically making it a weak APC.
The M5 was a piece of junk anyways. Ditto to the M4 Sherman.
From the accompanying photo, it appears to have been one of the turretless ones modified into an M4 artillery gun tow/ crew and ammo transport vehicle.
But as Napoleon observed, "Quantity has a quality all its own."