Is there a way to recover lost data during system transfer from 3DS to New 3DS XL?

I recently conducted a system transfer from my 3DS to New 3DS XL, however ALL downloadable content was lost. I redownloaded this content, but the save data from the redownloadable games are lost, including the first four purchasable games from Streetpass Mii Plaza, which I had almost 100% completed. Is there any possible way I can restore this data? (I used the PC-Based method for the system transfer, and I still have a copy of my original 3DS file on my computer.)

Thanks