Yamaha 115BET transom cut out?

I have a Yamaha 115BET outboard to fit to a 6.4m centre console boat. because the boat is in slightly cramped conditions at the moment and the motor is bolted to a stand in the corner of the workshop, it's difficult to trial fit the motor or measure the swing etc of it. I want to make the cutout in the transom as small as possible to get the best protection from following seas etc. I am hoping to get on with completing the glassing of the transom and agonizing over the motor cutout is holding me up.

The 7" deep V-shaped cut in the transom currently stands at about 20" at the bottom and 26" across the top, but that looks a bit too tight for the motor if it lays over to one side when tilted up. The Yamaha dimensions data says that this motor is 23.6" wide and swings 35 deg either side of straight ahead, but I can't check this with any great accuracy where the motor is stored at the moment, but it looks like the actual swing might be slightly more than 35deg - maybe??? Does anyone have an idea of the size of the cutout required to give minimal clearance?

Simon