I know of a 1903 with a Nickel scope in claw mounts that had that problem. The owner moved the scope forward about .5 in., allowing the flag safety to just clear the retainer ring and the ocular bell. There isn't a lot of clearance, but there is enough to allow the safety to be manipulated (using the right index finger).

I do not think a Buehler safety will work. Frank DeHaas shows an altered safety for a 1903 on page 108 of his book Bolt Action Rifles - Revised Ed.. The flag is basically inverted and extends back over the striker retainer nut.