Tires: 6.00-16 Trailer Tire, inflation pressure, trailer tire

Question
I am having a very hard time finding this tire. I am not sure what to do anymore. I was wondering if there is a size in today's world that is the same as my trailor tire, or would I have to replace the rim?

Answer
Derek,

I need some more information.  

What else is written on the sidewall of the tire?  In particular, load and inflation pressure.

What kind of trailer is this?  What is it used for?  How much load is it allowed to carry?  How much does it weigh?

I know you won't know the answer to all these questions, but I've written down everything I could think of that would give me a clue about what kind of 6.00-16 tire it is (Yes, there were different kinds!)
Is "Ply Rating" mentioned?  What about "Load Range"?