Well, Eugene. My son has some weights in his room. However, if one crawled away and he found dad using it as an anvil, LOL, he won't be too happy.
The dolly is something new to me. However, seems my best bet is to ask a welder to sell me a apiece of thick metal. I do have some business to do (other than the anvil) and will ask the guy for some of his scrap metal a few inches by a a few inches and then fix it to a piece of thick lumber.
Thanks for great suggestions.