I have four original Newton rifles, and two of them came fitted with the same Zielklein scopes in Redfield Senior mounts. They are very advanced for their day. They also have Newton cocking piece sights, which are unfortunately not adjustable for windage, though the front sights can be moved in their dovetails. The Newtons didn't require any bolt alteration to clear the low mounted scope and the safety is also evidently made with a scope in mind.

The only fault I find with your arrangement is the Greener safety, which I have on a couple of drillings and find very difficult to use, especially in unexpected situations. This could be remedied by installing a Buehler safety to replace the original bolt sleeve safety, which would have the additional advantage of positively locking the cocking piece.