I have one that I rebuilt from all new parts and components from David Kee. It is a special "one off" White Stripe Toploader aka the "Sebring Box". It has special gearing (ratios) that the standard TL does not have. For a more complete discussion of the special White Stripe TLs, go to David Kee's website
www.4speedtoploaders.com for that information.
David did the required machining for me and sent me all the required components. Everything down to the shift rails and detents are new.
If you are looking for a simple rebuildable unit, email me and I can walk you through what you probably will need to complete one.