It's been years sence I worked on that axle but I do recal seeing what yer sayin..it's like a washer but cuped. Yes, you can run without it, pack the hell outof yer wheelbearings and the grease that works towards the hub isn't going to be a problem. I put WB grease all over my hub's guts and coat the back side that faces the WB, figure if all the "space" is filled w/grease it can't go anywere.
I don't know the name of the washer and I too could never find them for resale so ran without..
Good Luck
