MinnFlyer and Deadeye had the best suggestion just redo the front now that you are still in the building process. by the look of your build so far you seem to have the experience the fix would be a pain but not that bad just time consuming. you could just cut the wooden mount off flush I would add 1/8 hard ply to the back of the bulk head and some triangle stock and mount a composite engine mount center the thrust line and add blind nuts to secure it in place, and by the looks of what you have there with a dremmel tool you could make a neat exit hole for your engine.