Very nice Mark. I am always a fan of stockwhips.
Make sure you roll the heck out if the core, especially as it is twisted. The kip bolster will help to "fill in the gaps" somewhat.
Plaiting from a yoke is actually very easy. With stockwhips the yoke is actually part of the keeper. Both the belly and the overlay have keepers. This provides for a stronger connection to the stock or handle. I cut the opposite side of the keeper long enough that when plaited over it will not loosen and also becomes part of the bolster. It also helps to provide the "swell" you see in a stockwhip.
Remember when cutting out a belly or overlay with a yoke start at the yoke end. Make careful measurements so that if you taper strands as you are cutting them out the taper at the same rate. I will use the first strand as a guide. Bevel the strands to improve the smoothness of the taper. As you cut strands the thinner strands can be cut from the inside portion of the kangaroo hide where the leather is strongest. Take account the stretchy parts and either cut them out of the hide or cut strands wider. After strands are cut wet and stretch them, resize.
Stocks or handles can be made from most anything. For full plait I use Bernie's method of a fiberglass rod covered with triangle sheets of newsprint, bound with sinew, and plaited over. For a half plait handle I get cane from Franks Cane and Rush supply in Los Angeles - http://www.franksupply.com/bamboo/
Keep up the good work!
Here's wishing you find time for the things you want to do, and for the things you need to do.
We see ourselves in our children and hope for a better future.