There were plans to do another Honeydrippers cd but Robert felt (and I agree) when Ahmet Ertegun passed, there was no point. As far as a cd of Robert's pre-zep days, there was never one. 66 to Timbuktu is an official release and has most of the songs on there which would be your best bet.
As far as Robert working with Sonny Landreth (which you have mentioned quite frequently) - I suspect if Robert was interested in that, he'd have pursued it. The fact he hasn't I would assume it's not a direction he wants to take at this time