g.day Dario,
just a suggestion , you could try using a hose clip of the right diameter, insert your c'clip & tighten to the desired size . Then with a drift of roughly the same size as the gudgeon pin( the drift could be a wooden dowel )lightly tap the c/clip home , mentally ithink this method could work,
cheers john.

i may have retired but i havent stopped yet, ive got one shed full of woodworking machines & hand tools(my other love, makin sawdust)my othr shed is mechanics tool chests stick &mig welders metal lathe 9 inch swing screw cutting so if icant buy it i make it,i hope im writing this in the right place,thats all i can think of at the moment, cheers & beers