A lead record is deleted on Marketo but available on SFDC. Is it possible to recreate the record on Marketo?
Yes, it is possible to re sync the record from SFDC to Marketo by updating the value of any field for that record on SFDC. By doing so, it will update the time stamp which in turn creates/updates the record into Marketo. However the newly created record will not have the past activities of the record that was present prior to deleting the record on Marketo. If the record does not sync back to Marketo, make sure it is visible to the Marketo sync user and that you do not have a sync filter in place preventing it from coming back across.