Original Air Evaporator Issues

First thing I'd do is contact supplier and see if it is actually correct one listed. Otherwise......

You know how to braze? AC guys (I used to be HVAC/R) use a product called "silfos" brand name for silver bearing-phosphorus brazing rod. It needs no flux on copper. You clean the copper, use an oxy-acet torch and flow it in. If it were me, I'd try and mod the tubes to fit, heat, bend, extend, etc

The sensor you should be able to re-route but be careful, as old as they are, likely weakoned. You can likely GENTLY work something like a knitting/ darning needle through the fins to give it a "place."

I've done soldering and welding, but not brazing. By the time I get the equipment for that, it would seem like I'm better off getting my old evaporator rebuilt - I have a new temperature sensor that I got as part of Original Air's AC upgrade kit.