1973 Norton Commando Value

Don't need no stinking zerk. Just an invitation for someone to fill the swingearm tube with grease.
Replace it with a bolt, easily removed and inject the proper oil in with a cheap plastic enema bottle.
All the oil will leak out in a sort time anyway making mess on the back wheel. The oil impregnates
the sintered bronze bushings and depending on mileage only needs replenishing 1-2 times per year.

And while you are working in that area of the swing arm cap try and resist fiddling with the threaded rod (part #26) that secures the two end caps. I don't know what the recommended torque value is but it can't be much in inch-pounds.
If you remove that threaded rod there is a real chance that the hidden end cap behind the inner primary cover will drop down making re-installation a problem.
Remove the stock fitting, inject the proper oil and replace fitting. There should be a tiny red plastic gasket on the fitting.

Mine has no threaded rod, but I really like 850's thoughts on the drilled out grease fitting because my big stiff fingers take hours to manipulate that bloody lock screw. Anything to prevent changing the bushings again and speed maintenance is a blessing as we all know.
My back tire can always use some extra oil to avoid excessive tread wear seeing as I only lube my chain monthly, and this oil flies off rather quickly facilitating proper traction giving rise to higher than desired tread wear.
Needless to say I'm going for it because I was considering lubing these soon.