for your oil consumption problem I would suspect valve stem seals, most likely what is happening is the oil leaving deposits on valves which will cause them to not seat well, this will give you low compression. Oil seals will crack over time from the heat I would suspect that is your problem for the oil comsumption. Your milage is low on that car to have ring problems..replace the seals with use of chevron gas should restore compression in cyclinder..
Bob