Moved to a new PC - empty notebooks

I have been using Joplin on WIndows, Android and iOS and syncing via dropbox.

I have just switched from WIndows to Linux and have installed version 1.0.175.

After installing on Linux I performed a synchronization and all seemed well. I have however since noticed that two of my notebooks are empty.

In hindsight I probably should have done an export prior to the move but with data stored in dropbox I didn’t think this was necessary.

I used new hard drives when I switched to Linux and therefore have my windows hard drive intact from before the change. Is there any way I can recover the notebooks that are now empty from this hard drive.

I hope I have provided sufficient information and I thank you in advance for any help provided.

Regards Scott