Restoring replaced local folders on Thunderbird

I use Thunderbird as my email client on two different PCs and had emails stored in local folders under the same name on both of the PCs. Wanting to merge the two emails completely, I copied the Thunderbird folder (by using the Troubleshooting Information>open folder option) from PC 'A' to PC 'B'. Every other folder succesfully got merged with Thunderbird on PC 'B' except for the folders with the same names. Naturally, I was asked if the files with the same names should be replaced or skipped. I mistakenly chose 'replace' and lost all the emails I had in the folder on PC 'B'. I just have the emails from the local folder of PC 'A' now. Is there a way to restore the folder from PC 'B'? I would highly appreciate any help rendered.