Even if you don't have that fire from long ago, get a divorce anyway.
Then the new girl won't feel obligated to you, she may feel you've sacrificed everything for her and that adds unneeded pressure.
And if things do pan out with your old flame, take it slow and live like a single man for a while, get to know yourself again.
That way you won't transfer all your expectations of what a relationship should feel like.
This is just a suggestion based on what I think would work for me. :-)
Then the new girl won't feel obligated to you, she may feel you've sacrificed everything for her and that adds unneeded pressure.
And if things do pan out with your old flame, take it slow and live like a single man for a while, get to know yourself again.
That way you won't transfer all your expectations of what a relationship should feel like.
This is just a suggestion based on what I think would work for me. :-)