It's hard to add much to this excellent thread but, in addition to the source for the aluminum screws I mentioned above, I found it helpful to cut some wedges out of scrap pieces of wood and plastic to help scrape the old RTV off and to clamp the cover to the bench top so that the new RTV can be squeezed deep into the groove using two hands.

I've had a minor oil leak for a long time. I just wish I had done this earlier.