I would consider asking on the “Commodore 64/128” facebook group – I know I’ve come across a few posts where people successfully installed the component mod into a SixtyClone board. For example, here is a picture I just found on facebook group of someone with same model board sixtyclone 250407 and working component mod:
Looks like their cable is routed differently, or maybe their cable was longer? Maybe they made a longer cable. I noticed in facebook picture one end of the ribbon cable has a grey connector where both of yours are black. Not sure if thats an indication they made their own cable.