Hello David ,
I have activated t he 4.2 version of the SDK for your account. You can download it from your SDK downloads page, but you need to browse all editions for the product. Please check the attached image.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items