You really don't need to worry about those measurements. Just follow the RCBS instruction sheet for setting up the sizing die and you're good. After sizing, check length, and if over 1.760" trim back to 1.750", chamfer and deburr. Otherwise leave alone.
One shot works great. Take 50 or so cases in a bowl or tupperware style container. Spray well. Shake, spray again. Enough gets in the necks to avoid sticking in the die. I squirt a shot up into the die to when I think of it. There's nothing magic about case lubing. If the case goes in and out of the sizing die without hanging up, relatively smoothly, it's good. Wipe the cases after sizing with an old undershirt.
If you want to shoot...shoot...don't talk! Tuco
USAF Munitions 1969-1992