But the question is what for? Does anyone still on that firmware, especially now we are waiting for the release of A4 untethered jailbreak from Pod2G that already done and now is under intensive tests by Chronic Dev-Team. Well, why not? The guy might find something by looking in the past to see if you can find exploits that may still be in there today, right?
But don't worry I will keep you informed if the iOn1c really is working on it and release the untether jb for iOS 4.3.5 for jailbreak community.