Restore deleted matomo Page

Hi,

we are hosting an Matomo Instance on Premise for a client who has approximately 25 websites.
Unfortunately the main website got deleted from tracking a month ago. Back then we looked for the reason and could keep a full backup from Matomo containing the data (webspace + DB) from the day before this one Website got deleted. And we immediately restored the corresponding row in DB table ‘piwik_site’, so that the Website is again being tracked. This all happened at the end of march this year.
Now we are looking for a solution for, in best case, somehow making the tracking data (before deletion) accessible again. For now everything we can access is tracking data data after restoring ‘piwik_site’ row. In the docs i’ve read that when deleting a site, Matomo isn’t actually deleting the tracking entries, because tracking data are all stored in one place with the other tracked websites.
Given that we have all data i think there must be way how to combine them again, thus we have a state somehow like before the deletion.
Can you help us with this issue?

As described above we have tried, what’s suggested in this thread:

Cheers from germany
Tim