Luxaire is a York company and is still in business.
Luxaire
5005 York Dr.
Norman, OK 73069
United States
Phone: (877) 874-7378
Email:
[email protected]
There should be a blower access panel at the bottom of the unit. If you open that you should see which side the filter is mounted on. If it's like most Luxaires it on the left side of the furnace.