Screwdown Coupler Question

[2ndmile]

I got an original Kit frame from Dan Sutton. It had most of the parts for the screw down coupler with it. Dan said that he just welds a new coupler over the old one typically but he said that mine was in pretty good condition. What are your thoughts on using the original screw down coupler?

Gage... I noticed in this photo that it looks like you are using the original couple with a new 'locking mechanism' (not sure of the technical term). Is that I am seeing?