Have you tried moving the shaft as though engaging a gear. This allows for more access to the holes. It is possible in situ as I replaced the oil seal to the shaft on my 33 a number years ago (I still have the special tool for inserting the seal if anyone wants to borrow it), I was able to get the roll pin started using a small hammer, surprisingly called a pin hammer, I then used a small G-clamp to press the roll pin in.