Linking...
Elements.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall CElement::Draw(class CDC *)" (?Draw@CElement@@UAEXPAVCDC@@@Z)


Dan,
You did well to find the error.
I got something similar earlier on in Sketcher. I gave up and started again. It worked fine the second time around, but I've started to make back-ups of the project regularly so that if it all goes wrong, I don't have to start from scratch.

Looking at your error message which I don't really understand, your remedy sheds light on it. The part CElement::Draw(class CDC *) must mean: look at the class CElement, and the function Draw()
.............

Here's the error I got:
1>Sketcher.obj : error LNK2001: unresolved external symbol "protected: virtual struct AFX_MSGMAP const * __thiscall CAboutDlg::GetMessageMap(void)const " (?GetMessageMap@CAboutDlg@@MBEPBUAFX_MSGMAP@@XZ)

So I guess that means I have to look at the CAboutDlg class, and the function GetMessageMap(), 'cept that there isn't such a function :(
Hmm...

Tony