Building COM Interop Library Using 4.0 Framework / VS2010?

A client of mine is only proficient in development for ASP Classic. They have recently acquired an account for a site originally written in ASP.NET. They are rolling the site into something they can actively maintain, but the site originally included an image handler that took dynamically changing data regarding water levels and outputs an image containing a graphical representation of that data. The requirement is to develop a COM interop library that can be registered on the server and called with CreateObject to generate the same image's byte array for output using Response.BinaryWrite. The COM interop library must be registered at the remote site on a Windows 2000 Server, and I can't make any assumptions about their having access to regasm/gacutil to accomplish that task.

The Difficulty

I've built the class library by creating a Class Library project in Visual Studio 2010, choosing "COM Class" from the template, and inserting my code to generate a class with a single public method to return a byte array when given an integer (well, enumerator, but all the same). Unfortunately, even on my own development machine after building the library and registering (regasm) and caching the assembly (gacutil), I can't make a call through Classic ASP to instantiate the object, receiving instead an "ActiveX component can't create object" error. And, of course, at the server site, the DLL can't be registered, the response being "Required module was not found."

Resources I've Used

I've already had a look through the following articles and haven't turned up the answers I need:

(basic steps) Walkthrough: Creating COM Objects with Visual Basic Build and Deploy a .NET COM Assembly .NET COM+ Interop Component with Classic ASP

What I Need

Essentially what I need is a bit of hand-holding on a kind of step by step of what it's going to take to meet the requirements and create a COM+ interop module correctly in VS2010. Creating the actual class object itself isn't terribly difficult. However, none of the articles I've looked through really discuss project options or build procedures with VS2010 or the .NET 4.0 Framework, nor have any of them really discussed if there are special considerations for deploying to older systems like Windows Server 2000 and the actual registration of the library on a system with only, say, regsvr32 on hand. Unfortunately, most of the information I find centers on ASP.NET 2.0 and supporting older applications while still in the middle of transitioning from ASP Classic to the new technology.