The process I used for this does not involve welding. While I think using a welder to do this would be quicker and probably have a better end result, I don't have a welder. So as an alternative I took this approach.
Here is what I started with.
I ground out the welds holding the right "mount".
Put the assembly in a vice and cut the right "tube"
I then drove the mount into the tube.
Once I had it positioned, I did the same on the left side.
I mixed up a batch of JB Weld...
...and using a putty knife, goobered the epoxy into both ends of the tube, cleaned up the mess, and taped off the ends while it cured.
This is what I accomplished on day one. As JB Weld takes 15 hours to cure, I went on to other things while it cured.
Earlier, when I dry fitted the pieces prior to potting them, I determined the correct length for the spacers and set them aside. Getting back to them while the JB Weld cured, I rough cut them to within an eight of an inch of their finished dimensions. As the mating ends are not parallel, I used a table top disc sander to finish it to the desired length maintaining relative angles of the ends.
Here's the finished spacer with the wasted piece.

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The difference between Genius and Stupidity is that Genius has its limits.
> Unknown
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