Is an oil lubricated Sturmey-Archer AW hub any different from the grease lubricated one?

On one of my bicycles the previous owner has replaced the gear hub with a later (1991) grease lubricated hub. I do not like these, as they require regular dismantling to replace the grease. I prefer the old ones with an oil cap. I was wondering if it would be possible simply to drill a small hole in the side of the casing and fit a cap to it, in order to convert it to oil lubrication. Would this work?