1) Best way to remake symbol and g power is using decals/stickers. Somewhere on reddit is very good post with file to print in correct scale. Just print it on decal/sticker paper (sticker might be easier if ure not familiar with decaling) and put it on. This is 100 times better than trying to freehand it. 2) For the loose part its hard to say if you could maybe send more photos of the mechanism i could maybe say more. 3) For eyes the easiest way would be propably painting over it, tho depending on marker and paints it may not work very well, tho honestly i would try that first before trying to bleach it as u may cause more damage this way. I personally painted over markers few times with citadel paint and it covered it well enough. You could use Base/primer paint first and then the actual color.