For starters remember that the OUI assignments are all about guaranteeing MAC address uniqueness among all manufactured devices using IEEE MAC addresses. The fact that we can map MAC addresses to vendors is secondary, especially considering the rate at which vendors buy each other out.
My recollection is that the IEEE allows private OUI assignments, meaning that the IEEE list of OUI assignments is guaranteed to be incomplete. Some third parties have undertaken to compile reports of OUI usage and may reveal some private OUI assignments.
I am unaware of any effort to map the entire MAC address to specific makes and models of equipment.
I hope this helps. Thanks. /criss