Pretty sure those G&H hopper cars were DL&W quqads. Lackawanna sold off all their fleet starting around in about 40 since industrial shipping of anthracite went down and retail coal dealers didn't want coal in large cars. In many places their coal trestles couldn't take the weight.
 
It could be that the railraod changed the angle of the slope shhets from the 30 degrees cound in coal cars to the 60 degrees found in cement cars since most comodities other than coal won't flow down a 30 degree slope. When EL converted cement cars to ballat cars thye increased the slope sheets even more and some of them had paltes added to cover the wider space between the top of the car end and the upper edge of the slope sheet. So  in essence, when coal hoppers were coverted to other uses the cubic fottage gnerally went down.
 
Chuck Yungkurth
Boulder Colorado.