restoring evap core housing

[woody45]

Does anyone know of a good product to use, or how to make the evaporator case under hood look new or close. I've still got the engine out & am redoing the under hood.
Also the A/C system had been changed over to 134a I would like to go back to R12. I know the expansion valve will need to be changed but the POA Valve looks orignal. How can I check to see if it has been recalibrated for 134a and how would I reset it for R12. :DOU:

Thanks for any help,Woody

[staged70]

I bought recon expansion valve and the POA set up[ for 134. Now I am hearing that it was not needed . I was told that there is a diffewrence inthe pressures for each gas. SO the POA will work I imagine so will the expansion valve