Yep, all you have to do is cut the rack proper by ~19 cm, drill & tap it for M14x1.5 (or is it 9/16 UNF?), and shorten the shell. Personally, I'm not sure I have the means to do that -- a cheap hand drill will hardly do to drill a 20 mm d12 hole in hard steel
What is the right way to drill a hole along the axis in a 50 cm long rod?