Replacement gas wall heater for old Customaire heater

We need to replace the 1950s Customaire gas wall heater that we have.
The problem is that the old heater covers only projected 4 inches into the room. The new ones seem to be six inches and we have a very tight hallway that the heater projects into. Does anyone now what type of heater we can replace this with? I don't think Customaire makes gas wall heaters anymore. Thanks.