If you notice to the right of the post there is a link to a flickr page I created where I have some old pictures of Shea Stadium in varies phases of construction. Please check back every couple of days as I will add pics when I can. You will also find an artist rendition of Shea Stadium with a dome on it. Before the Mets opened in 1964 there was talk about Shea being a domed stadium but that was scraped before construction started most likely due to costs.
You will also find an article from 1960 from the sporting news with a model of Shea. The picture in this post was taken in 1963 where the main frame of Shea was 80% completed. If you can notice the scoreboard has not been mounted yet.