Stucks screws and parts in general it's about patience, oil, more oil and various spray can stuff like PB blaster can make a differece too. The ideal scew driver fits the groove in the screw perfectly and has a sturdy solid handle. I bought a 201 a couple of years a go (three years this autumn). It has a screw in the bottom center below the bobbin case. I could never get it out, and I didn't want to force it too much, which meant I let it be but I oiled it regularly since there's an oil point there. Now and then I tried to loosen it, and a couple of weeks ago it was loose, no effort at all, just gently turning the screw driver all the way. I know it will loosen with a bit of oil and wiggeling it now and then. Since your machine has the direct drive gear and potted motor I'm guessing your machine will need cleaning and lubrication behind there.
I might have misunderstood you a bit in the initial post, but I see you are all onto it. Very odd about wasp nests, but you are not alone. I think read somone found a mouse nest in a cabinet a year or so ago.
Last edited by Mickey2; 07-24-2017 at 12:24 PM.