Vivitar 356 enlarger extension for long lenses

A lens board for the Vivitar 356 enlarger with a 2.5 inch extension to allow a 105mm lens to be brought into focus. Print in black filament, preferably ABS/PETG (it gets warm during long print sessions and PLA might deform). Threaded for M39 lenses, depending on your printer's tolerances the threads may be a bit tight. I cut a chamfer on mine to make starting the threads a bit easier.