Listen ATM apple is signing 4.1 & 4.3.5 so the only firmwares you can restore without shsh are 4.1 & 4.3.5
If your device's have bb6.15 installed so you are not able to install any firmware
always you try to restore you will gt 1015,1013 error which ends in DGU or recovery mode
So the only thing can bring your devices back
Put your device in recovery mode
edit the host files and delete the tinyumberella host server line
and then
restore your devices with custome 4.1
If your phone's are not with bb 6.15
so you have to install 4.3.5 first then you can donwgrade with a cfw so the best option is try to restore with CFW 4.1
