Does having the hole in the bottom of the comp housing mean that the comp has a grease fitting?
Almost certainly. As far as I am aware the hole in the housing was drilled by Morgan to suit the grease nipple. So if you have the hole in the housing you should have the nipple. Unless, possibly a Centa could have been fitted inside a housing that had already been drilled. Unlikely but we are talking about a Morgan.
Pretty easy to see the nipple through the hole or through the hole in the top where the steering rack sits.