I drilled it. It worked

I have been tasks with fixing a manfrotto tripod for a friend of mine who is hopeless at pretty much everything. He has misplaced the bolt piece that tightens to limit vertical tilting. I purchased what I thought was the correct piece from manfrottospares.com, but when it arrived the thred was too thick. Anyway, I'd like to know if it's possible to just drill the hole a bit bigger, only slightly, or would it be best to try and order another, more slender bolt? The piece in question that I bought was: R001,97. 2 Edged Knob With Bolt Spring And Washer 1

Any help or advice would be greatly appreciated.