re: Any painting/staining experts here?

Can't here is the problem oil base poly ambers over time from sunlight & you can't catch up and if you do match it it may match today but it will Amber over time and then it won't match your screwed you need a full sand and finish job. If you used a water base finish that dosent change color you may be ok most poly will stop ambering over time. You may get lucky but I doubt it