Ebay Evaporator for 74 Duster?

I'm getting ready to replace my heater core and re-seal my heater/AC box. The only replacement evaporator I can find is on Ebay. Has anyone used those with good results or know anywhere else to get a replacement?

My car was a slant six with factory air but none of the under hood AC stuff has been installed since the 318 was swapped in almost 20 years ago. Hoping to do that this winter. Looks like Ill be piecing together components since none of the aftermarket kits seem to work with factory AC.