Hi all, I don’t suppose anyone knows the part no. for the oval shaped rubber grommet that covers the access hole in the metal plate between the g/box & block please ? (see pic)I can't find a number for it (unless someone has a spare/unused one kicking about, please let me know). The one on mine had turned to plastic & was cracked when I took the g/box out last year & as I hope to have it finished this weekend this is the only bit I need, many thanks.