A tube can be placed over the weld and also welded. Note A Permanent joining of the pivot tube should be done last. Shorten and weld tower first. Washer will lay on top of lower pivot tube mount rubber. The radius is cut only to the 'flats' for depth.
Nuts face away from tower.
Display Machining Page Assemble making sure end play is out of pivot tube and swivel bracket, with transom bracket mounted tight to tower. Power head should be installed as it carries center transom mount. You can now mark hole in tower for lower tube mount and also mark the length of the pivot tube for welding. Use a stainless steel nut and lock washer to secure lower mount bolt, from inside of tower. I left all knobs and bosses intact on tower.