I just received in the mail from the fine folks at Dave Bean's 2 each of the "Grommet, radiator mounting, top - A100K6016F" and the "Bush, radiator mounting, bottom - A100K6017F" - pics below. Having just removed my radiator, the top grommets were a bodge job from the shop that built me a new radiator ~12 years ago so I didn't have a reference for the size of the proper grommets except for remembering seeing the picture Geoff linked in this thread - the ones I received in the mail seemed way too small from what I remembered seeing in this thread. Having spent way too much frustrating time unsuccessfully looking for this thread using LECs search function, I found it again after realizing that you guys across the pond have been spelling grommet as a cross between its "proper" spelling and Wallace's companion

To my relief the sizes match as I forgot that you are all in the process of "metrication" and that the ruler in Geoff's liked picture was in metric denominations

Grommet, radiator mounting, top - A100K6016F

Bush, radiator mounting, bottom - A100K6017F

Bush, radiator mounting, bottom - A100K6017F