speedo and rev counter oooot!!! dse..

Hi landy lovers.. went over a sleeping policeman a bit lively the other neet.. and the fuel gauge needle fell off!!!!... now i took the dash apart and found the needle.. but the two dont want to go back together again!! so there is proberly another part missing.. but i canny find it.. if i unplug the electric leads will i loose any info?? will it need to be set up again if i did unplug them?? any hel would be great..

you may loose info like fuel consumption, but all milage info etc is held in bcem module