Time capsule Back up erased after migration photos issue.

I cloned my MacBook Air to an external drive (via techtool pro) then migrated to my iMac using the external hard drive. (I should have migrated from time capsule). Then I set up my time capsule for backups and consented to inheriting my backup history. It is only at this point I realise that quite a few of my photos (in Photos App) were missing some data, only thumbnails being intact. (I have checked all Photos libraries) Looking for photos backed up on the time capsule I find that my old back-ups have been erased as the new iMac is starting a new backup on the time capsule. The data is not there on the external drive and MacBook Air has been deleted and disposed of.

Mac OS High Sierra on both Macs.

Is there any point in getting any software to unerase files from my time capsule in the hope of recovering some photos?