Good job on straightening it!
To get rid of the oil use some acetone. When it comes to sinewing it's a good idea to degrease the whole back anyway with osage. Again you can use acetone or just plain old hot soapy water. You will see an amazing amount of yellow come off! Keep going until the water runs pale yellow...I do mine in the shower
Your recurves look pretty long to me. Remember that the benefit of making a bows tips recurved is the improved string angle so my advice with them is always go as short and sharp a bend as possible. This allows you to really shave them down and keep the weight low.
Also when you sinew it string it backwards and pull it into more reflex before adding the sinew. Another tip with sinew is to make sure the back ends up as crowned as you can make it. Try trapping the back before sinewing and then just putting the sinew on the central section. These things are to try and really strain the sinew, it can easily stretch way further than the wood can bend so doing all these things really gets the most out of it.
Good luck
