My understanding is they have similar kits grouped together. Then it lists the busings for that kit, drill bit size, and all of the dimensions. You have inlay kits for a Sierra kit but want to use a Gatsby click kit. According to the chart, both kits have the same size tube and bushings. The only difference I see is the tube for Gatsby click is .04" longer then a Sierra. You should be fine using the Gatsby kit with those Kallenshaan kits. Hope this help.
Jamie