Did you ever get an answer to your question of how to get a story metered, one you wrote before you were a MPP member? I aked the same question, and a follower of mine: Tze Lin Sam, gave me the answer. It is simple, and here is a link:

https://medium.com/informatics/how-to-earn-money-from-old-articles-in-medium-f1d30ed233cb

I had just written a story about this same issue, and she, Tze Lin Sam, was most helpful

https://wireeditornewman.medium.com/medium-help-desk-i-need-help-25990c7d1244

I hope this helps,

AL.