Servo Skull measure tape with LASERS! Thats right. Ive finally customised and painted those old things.
It took me literally years to get back to this project 
Ive bought those tapes many years ago when they showed up as a limited add-on to new 40k edition (5th or 6th i belive). They were called munitorum tape measures or something like that. They are actually still listed on japanese page: https://www.games-workshop.com/en-JP/Warhammer-40-000-Munitorum-Tape-Measure
Anyway ive immediately got this feeling that its missing a laser pointer. So now ive finally decided to put this plan together.
Ive bought some cheap pointer, only criteria was to get the smallest one i can find. Ok, ok, there are probably smaller ones out there but this one was good enough. Toughest part was to remove area of the skull where the pointer shoud fit in. Ive did it using a drill. Ive picked one the size of a pointer that ive bought. It was tricky as i could easily overdo it and remove too much of it or damage some other details but it turned out fine. Ive put some magnet inside so the pointer is removable. Ive did it mostly to make battery exchange easier. This detail isnt looking very nice, but i didnt want to spend too much time on it. Ive painted it up to look like bloodied flesh/parts of brain to cover up the bad craftsmanship
After that ive just painted the whole thing and applied a thick coat of varnish.
Ive made two of those actually