OS X doesn't need a boot-loader (for itself, on a hackintosh it does), so you could just make a .dmg out of your partition, and save it on an external disk.
I recomend you use retil, not iDeneb, and if you want SL you have to start out from zero.
I would check which kexts you used for iDeneb, that will help a lot to install SL (you just need to find the equivalent).