Ugh. I know what you mean about using the shorter baseboards. I installed some hardwood and replaced stair treads in my 105 year old house, and some of the original baseboard was damaged. You can't just go to Home Depot and buy that old 8" baseboard!
I didn't want to sand and re-paint the whole length of the wall, so I ended up making my own baseboard. I needed two router bits to recreate the pattern of the original, and it looks close enough. I would not have been willing to do more than about 10 feet of that though!
What I've learned so far:
- don't start working on the car unless you have a ride to the parts shop.
- whatever you're doing, Mango's guide is probably right.
- the Bentley manual skips steps. LOTS of them. Don't tear your hair out when the next step makes no sense.