i have a manual but it doesn't properly show the upper blade seat, it shows it fixed. it isn't. the whole bracket slides up and down to control the size of what your cutting. part of this bracket, made of cast aluminum, holds the bearing assm which adjust in and out, not fixed, plus it has a square hole receiver for the blade seat which also adjusts in and out. this part is broken. this part is cast alum and it slides up and down, plus has two groves that allow the bearing shaft to slide and the upper seat to slide. my book shows all this as a simple fixed part, i probably received the wrong manual with the saw. there is no tag on the machine to identify it, i bought it about 10 yrs ago. help please.