During a database attach migration from Sharepoint 2007 to 2010 a report can be obtained by running Test-SPContentDatabase command. Missing webparts are just indicated as GUIDs without any association with installed webparts. This tool allows you to match webparts with this IDs.
Commercial Use
Modify
Distribute
Place Warranty
Sub-License
Private Use
Use Patent Claims
Hold Liable
Use Trademarks
Include Copyright
State Changes
Include License
Include Notice
These details are provided for information only. No information here is legal advice and should not be used as such.