Orange Hand "Freccione" Explorer II 1655, Keep or Sell?

[Freccione 1655]

Hello Everyone,
I own a model 1655 Explorer II. This is the orange hand Explorer II refered to as the Freccione or Steve McQueen edition. I have just recently found out that this watch has become a highly desired collector watch and valued at up $20,000. Does anyone know or have an opinon if I should keep this watch for an investment or sell it now? I have asked a few jewelers and can't get an honest answer from them. All they want is to buy it from me. I would like to sell it, but am not sure if they are still increasing in value, if so, I would keep it for an investment. Because I just found out about it's value, I don't know the history of this model over the past few years. Has it been increasing in value or has it peaked out now? I'm also concerned that it may drop in value over time. Mine is a 1973 and I have owned it since 1980. It's in #1 condition as I hardly ever wear it.
Thanks, Eric