Also, in doing some research in this kind of thing a while ago, you will find that not everybody's family has a coat of arms.
Just because your last name comes up with a match, doesnt neccessarily mean that is the coat of arms for YOUR family, even though it has that name. If it worked that way, all the Smiths in the world should be severely deformed and retarded due to all the inbreeding that must have gone on to get a family that huge from the same lineage.
Do what someone else mentioned. Trace your family members back as far as you can go.
The first Saltmarsh to come to Australia was William Saltmarsh. He was shipped here for grand larcenary on the Alexander. He is known as one of the people who captured the first bushranger, a huge west indian guy that was named "Black Caeser" He was a huge guy and mostly stole food from other people because his convict rations werent enough. he escaped and become the first known bush ranger. William captured him, then he escaped and was captured a few other times until someone shot him.
I would like to try and trace the Saltmarsh family back beyond that, but I wouldnt have a clue where to start. Some geneaology place I guess. My grandma traced her side of the family back pretty far. I could always ask her for advice.
The Peden's have a cool back history too. I would like to trace that also. I know a few things from the Peden history, but would love to know more.