Upgrading to latest MarketPress: how to preserve variable size/price data

Hi, this is Melissa writing on behalf of my client, Mike Tobias. He runs an ecomm site with MarketPress 2.9.5 and we are in the process of upgrading to the latest version. We ran through the upgrade process on a test server and see that when we export/import our products, we lose the variable sizing and pricing, etc. Is there a method for preserving this data when we go live with the upgrade? Can it be done via the database directly if it can't be done via the import? We just want to avoid having to re-enter all the product variants post upgrade.

Please if possible reply to // email removed by staff //. Many thanks for your time and attention.

Thanks,
Melissa Cahill on behalf of Unique Fire Stop Products