I finally got around to doing this mod. Thanks to ToyQuest for leading the way and coming up with a great idea.
I took a few pictures and had a few little things that I did that other folks may want to consider if they'll be wanting to do it too.
First off, is the disassembly. Before you go yanking the brake pedal off the splined shaft, you may want to be sure that there is a match-mark on the shaft and pedal so you will be easily able it back on at the same angle. I can't recall if this mark was already there, or if I made these marks when I disassembled them previously. Either way, just pay attention to their relationship beforehand
Also, be aware that when you do remove the brake pedal you'll need to
fully remove the 10mm pinch bolt, as there is a groove in the middle of splined shaft that helps lock the pedal from slipping off the shaft, even if it gets loose. You can see that groove in subsequent pictures.
Some people have complained about how difficult is is to get the cotter pin out of the master cylinder pivot pin, because the cotter is in the back side. I think that is because they don't know how easy it is to just remove the entire footpeg assembly, master cylinder and all, from the frame. To do that you only need to remove the two bolts indicated here.
Note that your upper bolt will be regular silver colored, not blue alloy like mine. The prior owner replaced a lot of the hardware with some blue bling alloy stuff, and I'm too cheap to replace it all back.
Anyway, after you remove those two bolts the whole footpeg assembly can be pulled out and you can easily get at all the stuff on the back side without laying on the floor.
This picture also shows the groove in the splined shaft that the 10mm bolt locks into well.
I went rummaging through my spare hardware and found that I had some 1/8" NPT Zerk grease fittings laying around from some prior project. This is what you want to install the zerk fitting directly into the pivot shaft with no pressed in spacers.
The outside diameter of a 1/8" male NPT fitting is .405". The inside diameter of the counter-bore in brake lever shaft has been said to be .394". You'll need a 1/8" NPT tap, which I also happened to already have on hand in a cheapo old Chinese tap set. As you may already be aware, NPT is a thread style used in plumbing, intentionally tapered so that as you tighten the fittings you get a leak-free joint. This means that you can adjust the depth of the thread taper to orient the angled zerk fitting in the direction you want.
Here I am cutting the threads. With a little trial and error I was able to get the taper cut deep enough so the zerk sticks out at the desired angle, downward when in its installed orientation.
Next I drilled two 3/64" holes through the shaft, in the area of the groove in the center of the bearing surface. I used my drill press, but you could just do it with a hand drill, after center punching the marks, and a steady hand. Now just add a little Teflon pipe tape on the zerk's threads.
And after the final assembly, gotta make a bench test
When reassembling, I followed some other folks lead and put the master cylinder pivot pin in from the back side, so the cotter pin will be more readily accessible without having to remove the foot-peg bracket.
But I'm thinking with the new grease fitting, I may never need to disassemble this particular assembly ever again!!