What have I missed in this custom format copy and paste?

Question

My copy code:

if OpenClipboard(mainwnd.Handle) then
  MemHandle := GlobalAlloc(GHND or GMEM_SHARE, Succ(StrLen(pLclCopies)));
  if MemHandle <> 0 Then
   Begin
    try 
     StrCopy(GlobalLock(MemHandle), pLclCopies);
     GlobalUnlock(MemHandle);
     SetClipboardData(cf_LocalVar,MemHandle);
    Finally
     CloseClipboard;
     GlobalFree(MemHandle);
    end;
   end;

and my paste code:

if clipboard.HasFormat(cf_LocalVar) then
  begin
   ClipBoard.Open;
   try
    MyHandle := Clipboard.GetAsHandle(cf_LocalVar);
    LocalsTextPtr := GlobalLock(MyHandle);
    CheckForCopiedLocals(LocalsTextPtr, TextPtr); //What I do with the pasted data.
    GlobalUnLock(MyHandle);
   finally
    Clipboard.Close;
   end;
  end;

My goal is to copy not only text from a special editor in my program, but also to copy some underlying variable data related to that editor. Most everything seems to be working fine clipboard wise - I'm seeing my copied text, and the 'cf_LocalVar' format appear in the ClipBook viewer on windows.

It's when I get to the paste side and the line LocalsTextPtr := GlobalLock(MyHandle); doesn't get the copied data from the first bit of code. I see that it makes it into pLclCopies but then can't be sure that it's stored in the clipboard.

NB I have left out emptyclipboard from my code as this would get rid of the cf_text that I need along with the cf_LocalVar.