https://velo-orange.com/products/gra...kset-24x34x48t
Is this your crank? The recommended bottom bracket spindle length for it is 124 mm JIS which is quite long. Is that what you have? I am only asking because your question didn't include this information. Also, you don't say what rear cogset you are using and what chain you are using with it. A solution might be as simple as using a narrower chain with flush pins rather than laboriously filing pickup pins on your chainrings. If you are using friction shifting you can use as narrow a chain as possible no matter how many cogs you have in back