Project Work on a Legacy VB.net Web Application

I need some work done on a legacy VB.Net Web Application. The System is build as a Single Page App it is technically a Web Forms system there is nothing on the markup side and does not use any standard .NET controls. Pages get built by back end VB Code. It also connects to an old version of SQL Server (2000). The System is distributed across several servers for various functions though the primary code base on each is the same or similar. The application is a content management system for website hosting and content syndication. The System is build on X-AspNet-Version: 2.0.50727 (VB Code) and writes our pure HTML files to various locations. My former developer assures me that once a .Net Developer gets into the system they will be able to figure it out but it will seem a bit strange to them in the beginning. What I am specifically needing help in is getting the system to support HTTPS under customer domains. This will be done through an nginx relay. The problem is there are several instances where absolute paths are used with [login to view URL] This is done through a rewrite process that changes the resource url from a static constant to a customer variable based on what features are enabled in the account. What we are looking to do is change it so that resources like images in the website are not remapped to customers domains but use our https path to the images. We want a function that would allow us to enable https under the customer domain and would then re-write the resources (images, css files, java script, etc) if the customer wants to pay for the set up. This is just one of the projects (most pressing) that I have in regards to this Legacy System and would like to build a relationship with a Freelancer whom I can count on for future projects.