Finally got some spare time to finish the 3rd mower storage rack ,this one completely bolts together (6 parts) used up some more scrap metal and over 4 kg of welding rods .
A lot of welding but only $50. in materials ,it's made for Victa 18 mowers so the blade plate sits below the horizontal rack.
I think the two 1/4 inch bolts per corner on each shelf should be strong enough.