I wonder if you can write to the exchanges an tell them you are the CEO of STEEM? Technically you wouldn't be lying as Steemit is a private company. You own a STEEM node and STEEM is decentralized.
If you say that you are an executive member or CEO, they will respond. I have a friend that is working to get his coin listed on an exchange. He emailed the entire top 100 exchanges and told them that he is the CEO which he is, but his coin is not listed anywhere. He got a huge number of positive responses. All he has to do now is pay the listing fees.
Just take all the vests that are voted to your witness and convert to equivalent SP. Then convert that SP to dollars. That is the valuation of your executive position.