Rear wiper removal - grommet size

I'm currently removing the rear wiper from my Coupe and I'm having trouble finding a correctly sized rubber grommet to fill the hole left by the wiper.

I have a few different sized grommets but the closest I can get is a 38mm grommet.

Has anyone on here de wipered there coupe and would have any advice?

I was going to put a bead of silicone around the glass and then fit the grommet. Would something stronger like tiger seal be better?

Thanks

This was covered over here:

https://www.fiatcoupeclub.org/forum/ubbthreads.php?ubb=showflat&Number=1627047&page=39

Ebay link

https://www.ebay.co.uk/itm/35mm-BLACK-PL...RS/361964220152

Thanks for the links Graham! Ordered that grommet just now.

Nice one, been thinking of this for a while.

I found some years ago blanking plugs for bath/kitchen sink sirve the task very well, available in chromed and white PVC, easily paintable the latter.
They are the right size (at least here), “just insert through the rubber grommet and the tight” job, perfect sealing and cheap as chips also.
This
or that.