the ones that hold the top and bottom halves of airbox together that test you thumb strength !!! Can you buy them new anywhere ?
vwheritage "Air filter box clip" look carefully to see if you need the a or b. https://www.heritagepartscentre.com/uk/191129797b-clip-for-the-air-filter-box.html https://www.heritagepartscentre.com/uk/191129797a-air-filter-box-clip.html