In 1936, Dr. Naismith had a portrait made by his friend and fellow professor Ed Elbel. Prints were made of that portrait. This is an example of that print, signed by Naismith. The print measures 7.5" wide x 10" tall. I was purchased in the Heritage Naismith auction on December 8, 2006 and came with a Letter of Authenticity from PSA/DNA.
I have seen several examples of these signed Elbel prints since that Heritage Auction. In my opinion, this is one of the better options when it comes to getting a reasonably priced piece of basketball history.
There are also various unsigned example of Elbel's Naismith print. These are all great items of the period and are worthy additions to any collection.