trying to find a replacement heater core that FITS!

I'll take a photo sometime today and yes, there is nothing sticking out of the firewall except for two hoses going to the engine. The whole unit is very compact and completely self sufficient.. BTW, my Signet is insulated well under the carpet and the carpet extends from under dash near the windshield to the trunk. Its just the way I needed it to be with the engine and road noise. The heater unit is under the dash off center towards the passenger side and the hoses run through the firewall in front of the glove compartment. Along time ago I removed the original heater along with the original vent boxes on each side because they were troublesome as I am sure you know what I mean with those doors. I than installed a Vintage Air and heat system which I discarded two years ago and installed this heater. Even though my car is black on black, I just could see needing AC for one month of the year. I'll try for photos within the hour...