If you have preserved user_ids by reloading the old wp_users table, then you can export the transactions to csv and reimport them.

You bring a valid point, that exporting and re-importing should be based on emails, not user_ids. I will work on the exporter/importer function so that this is easier.

For the time being, do the following: Copy the tables wp_users, wp_wallets_txs and wp_wallets_adds from your old installation to the new one. Everything should work nicely.