For sale are used finned heat exchangers. Each is sold separately from the "select" drop down menu. The units are dirty and dusty and have bent fins. The tube ends are pinched shut.

--Finned Area 10-1/2 x 9 x 1-1/4", Tube O.D. 0.325, 

--Finned Area 10-3/8 x 9 x 1-1/4"; Tube O.D. 0.395, 

--Finned Area 5-1/4 x 5 x 1-1/2"; Tube O.D. 0.375

If you have any questions just ask.