Can someone help me? I'm building a newtonian telescope, 8-inch, f/6, secondary minor axis 1.5 inch. According to the instructions I'm following, I need a 1.25" focuser with minimum fully racked in height of 1 3/4 inches. Problem is, I just can't seem to find a focuser with those specs. Are they that unusual? Could someone send me a link if you're able to find one? Thanks.