O-Ring for needle of GX-15 Kyosho Ferrari F2004 engine the measures seems to be (needs to be verified by me as soon as I receive the O-rings) ID: 2,6 mm CS: 1,3 mm
Thunder Tiger TS-4N replacement of gear shift spring and ball The ball has a diameter of 3 mm the spring is 6 mm long, 3mm diameter and 0,5 mm thick, ball available here https://aliexpress.com/item/1005004107735483.html for the spring you have to search a little bit do not have a link right now