Couple of things I think you could improve are extend the bearing surface of the moving head. Extend some bar up the uprights and tie them front and rear. Looks like you have plenty of room. Perhaps a centre piece in that wedge? Make some more bolt-on attachments like a round bar to use as a press and a drop in table for use as a press.
Also a suggestion that you wear gloves and long sleeves when welding, shoes might be an idea as well. UV damage is accumulative and it would be a good idea to get into the habit of NOT laying your welding cable over a fresh weld. Cable ain't cheap.
You did ask aye?