I have no reference of them. They are from japanese cars i think. I just went to parts shop and picked those from the "salvage bin".
But the one on the left is smaller than the one on the right.
The one on the right is 10,75" x 5,625" x 2,1" , approx.
The one on the left is 9,5" x 5,1" x 2.1" , approx.
Try to use airspirit's heatercore database for a match.
http://www.pullmanford.com/heatercores/
As far is the tubing. The one on the right was cleaned and the brass tubes replaced by barbs. I'm doing the same with the other one when i get more barbs... but it's not a priority .
I got both just in case one leaked, or i screw up.