In answer to your first point and as you have found out, yes the RC and RD manuals are different. The RC 32MA301 the RD 32MA3600 however where things are common you do see the RC pictured in the RD manual. Even some spelling mistakes are common to both manuals.
If you have an RC manual the centre picture on page 93 shows part (6) oil seal, (7) Buck-up ring, ( Gide bushing, (9) Slider bushing, (10) Snap ring, (11) Oil lock valve and (12) Fork piston. This diagram is basically replicated in the RD manual except it is split in 2. Parts 6, 7, 8 and 9 on 1 picture and parts 10, 11 and 12 on the second picture, however the picture far right on page 95 does show a difference. The RC manual shows Dust cover, Snap ring, Oil seal and Back up ring but the RD manual shows Dust seal, Sponge seal, Plastic washer, Snap ring, Oil seal, Back-up ring and Slider bushing. If I remember correctly the Sponge seal is just a fibre washer (what you describe as Holder, Grease 51438-MB9-781) and the plastic washer is just that (what you describe as Holder, Washer 51439-MB9-781).
Its been a long time since I‘ve taken my RD forks apart but I do recall when I first saw the fibre washer I thought it was something that had been added by the previous owner just to mop up any oil leak. I personally don’t think it would cause an issue if it were left out.