Nope, just checked my books, and I was mis-remembering the break points. It's been 50/100/250+ for quite some time now. Thanks for straightening me out Cray!
As far as a grav deck on the Scout, the largest diameter the deck plans I was working on has 82 meters internal, with a one meter thick hull that could mean 84 meters is what to use for the construction rules (both are under 100m, so no worries, really).
Using that extremely useful "Comfort Zone" chart in the paper Von Jankmon linked, it looks like a ~40m radius can't quite get to 1G at 4 rpm. The good news is that it looks like 0.5G is possible in the 2-3 rpm range, and the AToW rules don't inflict major penalties until you're below 0.2G. Of course, the rules are silent on what percentage of your day you have to spend in less than 0.2G to receive those penalties (they were written assuming low planetary gravity).
Construction-wise, this actually could cause a problem with the KF core. I took the "door" looking part of the nose (that's off centerline) as the core replacement/maintenance hatch. If the core doesn't have to be the entire length of the ship, this could be essentially ignored by just leaving a "tube" that could be aligned with the core when the grav deck isn't spinning. If it DOES have to be the length of the ship, then I need to start over (which I basically have to do anyway since I lost the thumb drive that had the most recent Visio file) to put the core on the exact centerline. That would still leave a bit of a trick for getting to and from the grav deck, but it's not insurmountable.
At the very least, a grav deck will help soak up some of the HUGE volume available inside even a "small" JumpShip like a Scout.