Hey dolphod,
Saves should automatically sync over to the newest version, however, there are cases sometimes where it doesn't.
If you have your old AHITR folder, the saves should be in: AHITR\Game\Saves
If you don't have the folder anymore and you're on the same PC and it hasn't been formatted, you can find your AHITR (and other Renpy saves in): AppData\Roaming\RenPy\AHouseintheRift
You can drag those saves into your new AHITR directory (AHITR\Game\Saves)
If you can't find them, this is a save from our official Discord. It has everything completed up to 7.4. Unfortunately I don't have a save at 7.0 so this is the closest I can do for you
https://mega.nz/file/XeYw2aCS#KargzUmsbstF6yIh9nsLMZgVbAJJhNdU2ZtenvxZDxQ
You can download that and drop it into your AHITR save folder (AHITR\Game\Saves)
I know it isn't exactly ideal, but I hope this helps o/