all the parts sidle together easily, the nut you need is a 3/8 by 20 nut, the outer size of the nut is 14 mm on flat sides, should slide in easy, all parts are snug, little to no glue required

this is the link for the ink board that fits
https://www.amazon.com/gp/aw/d/B0BXQ4SK7Y?psc=1&ref=ppx_pop_mob_b_asin_title

I recommend using a piece of double-sided sticky tape on the ink board to hold it still