I was just wondering about re-sealing the TC cover. I realise you've got to take the engine mount off, but most of the bolts look accessible. I suppose it's the ones down at the bottom that you can't get at. With a socket, at least.

For a long time I have made it a habit to replace ordinary hex-head bolts with Allen bolts. A long time ago a serious mech eng told me to use them in alloy because they're made of higher tensile strength material and they don't stretch like ordinary bolts when tightening = less chance of stripped threads.

Secondly, it is a hell of a lot easier to get the short end of an Allen key in there, than a spanner or socket.
I find myself wondering if the bolts were replaced by Allen bolts, it might be a lot easier to get the TC cover on and off