Question on cab heat shield/deadening material

[Lost81c10]

Need some help; I have a couple of questions,

I took out my seat to clean the carper and want to replace the sheet of asphalt as this makes the cab stink like I have been working under the engine all day, now I speculate the asphalt sheet is what is causing the odor because while everything was out for cleaning the cab had no smell but once I put the asphalt sheet back in, the smell came back. I don’t want to put the carpet and seat back in until I replace the black sheet. Now I was surprised that the floor looked as good as it does. I was ready for rust spots.
My questions are:
Q1 - Which of the two is the sound deadening and which is the heat shield (I have an idea but want to be sure)?
Q2 - If the asphalt sheet is the heat shield, what material can I replace it with that is not asphalt base?
I have looked into RAAMaudio, SDS, Dynamat, Fatmat, the new Rhinomat and the likes but not sure if they are also heat shields suited to replace the factory heat shield:
Any help would be appreciated and please correct me if I am wrong on the above mentioned ones.