Never seen a Mulfab steering bearing with a grease nipple fitted, not to say it can't be done but not much material to threaded? Whenever I fit a set I drill the stub axle after first marking the bearing race height from Peters bearings and allow grease to bleed through from the inside of the bearing. In fact the MMC started adding these bleed holes shortly after fitting their version of the bearing, initially one hole, then two and latest cars have three bleed holes. A very simple job to do even with a hand drill but of course a drill press makes it simple, I have even drilled stubs for a few guys on here ;-).

BR Colin
Who used to be a Spanner Juggler