Thanks Lyndon, your friend's approach is my plan B approach, and offers some extra benefits, primarily the extra storage.
Last night I spent some time with various searches and found several good ideas including a simple slider.
Other than that what I found is several people having issues backing fivers some understanding why, others just frustrated such as Bob, and either resigned to live with it or moved on to other things..
Also found that Greg H never has anything positive to say about fiver's or for that matter much of anything else other than his expertise as a driver.
Lastly I continue to be amazed at the proliferation of useless information offered by this forum.
gmw. Why do you think I posted my original question??? I even stated I was looking for history of others efforts, although I think you are a bit paranoid as to insurance and such.
For what ever it's worth I have spent my life or at least the the last 50 years of it in medal fabrication industries so I do have a basic understanding of stresses and such. Just hoping for some history and insight on other attempts, not looking for a collection of unrelated garbage..
The questions was "How to convert a fiver to a bumper pull." Not how many ways can you find to pull a fiver.
Thanks to all who have offered constructive suggestion.. The rest of you ... well what can I say? Enjoy the ride.