Use at own risk !
This backup contains : aboot, boot, cust, firmware, product, recovery,system,vendor, version (if needed other files can be provided but with those ones you should be able to restore your system backup)
TWRP BACKUP : TRT-LX1 : https://androidfilehost.com/?fid=962187416754455038
Also the TRT-LX3 can be found here : https://mega.nz/#!Bd5W3ALI!cJ_3F5pIS...62VExSL9D3zb8c
Btw, if other backups are available for other Y7 models, feel free to share here as a restore point