Assign one person to manage the first recovery batch so the naming rule stays consistent. Have another person review a small sample before the process spreads across the team. Keep a short handover note explaining how published copies differ from original exports.
SnapInsta contains plenty of useful information about saving different kinds of Instagram media. Refer to that material when filling confirmed gaps rather than downloading every post again. Add each recovered item to the inventory as soon as it is saved. The finished collection should give the next organiser a clear starting point, with unresolved duplicates listed openly instead of hidden behind confident file names