DiskDrill have this option too, virtual disks can be mounted and deleted files can be recovered. A virtual disk can be opened as a compressed file too, and it is possible to search through its files. I did both things, recovered several gigs of files, compressed files either, and searched for the wallet.dat file, but nothing appeared. Even I searched for the word "wallet" inside documents, but it only appeared inside a .jl file, but nothing related to 50miner or similar.
Also searched for 50miner, key, seed and several words related but nothing useful appeared.
I don't remember recovering the wallet.dat file; I didn't know anything about mining at the time (and I don't know much about it now) and since 50btc is closed there is no way to recover it know.
I think my bitcoins are lost like tears in the rain

Thanks so much for your help!