Hi PK,
Like everybody mentioned here already it is not possible to migrate old tickets
the best option would be to do system copy if you are migrating to new hardware and then perform the complete Upgrade using SUM etc
further, create new transaction type as per process in this system
you can check my blog as well for some common errors and issues during upgrade
Upgrade Roadmap - Solution Manager 7.0 to 7.1 with Service Desk/ChaRM
Thanks
Prakhar