There are several examples out there including AustinHarris.JsonRPC which include fully packaged JSON-RPC servers.
Those that I can find for clients seem to just use Byte stream reading. I'm trying to find a simple implementation using a HTTPClient as I understand it to be among the most efficient means of JSON requests available in .NET
Essentially I just need a simple outer shell to handle the model for the generic JSON-RPC structure and the sending and receiving of the data. The data that is returned will then be extracted from the outer JSON-RPC object and converted into strongly typed entities.