As you see I'm not down there yet
Well, I got right Tuit after I sent the above & exactly what I was afraid of happened.
It took me 15 minutes of trying different ways & I finally got one end loose & could hold it up long enough with a very old small knife I've had for a hundred years. I was popping the rest loose with my smallest needle nose & it was gone. My hands were hurting awful by then & it's a really hard place to work in (on my knees, of course) with drop light shadows & bifocals added in for extra spice. I should quit doing crap like this.
I've been down there since trying to find it with magnets & lights & I'm positive it's not in the lifter gallery. I think it must have gone right down the oil return hole (of course) which looks plenty big enough. And I'm positive it's not on the floor. I'll go down in a while & search that side of the whole engine itself again. Surface tension of the oil would stick it to metal just like glue which would explain it not being on the floor (the bike is on an old kitchen rug which would show the clip up really well).
Another part added to my list. I could just delete that collar, I suppose, but I prefer killing the engine with it rather than the key.