Spring cleaning!!! I have a welding jig that I used to make my 12.5" 9 point flotation mirror cell. Once welded the cell will fit a 14.5" inner diameter mirror box. This is what "The Dobsonian Telescope" book suggest you make before having your mirror cell welded. Worked perfectly for me. I also have the layout of where all the holes should be drilled and tapped in the cell.Use 1/4" steel flats and 1" square steel hollow tube to build it. Asking $24.00 shipped to CONUS.
Thanks for looking,