A Few bits and pieces correct here and there;
OLD FELLA
Does not the B767-300 have a hydraulic ram which extends with gear extension and which acts as a tail scrape protection/notification device?
Yup it does, but as NSEU mentions not so much of a notification device unless u manage to bend it, break it or collapse it.
SUNFISH
From memory the B767 has a crushable little sacrificial skid plate on its bum .
Yup it has this too - but this is on the end of the tail skid. (I am not sure if that's what u meant or actually a skid plate along its rear end) I am not sure what is made of but it is a white block on the end of the skid. It's in the Red area of the QF logo/paint scheme, so the red paint comes off and it should show through with white scrape marks.
... compared to say the 738 it has a crushable cartridge in its skid and a little green symbol showing status of it.
NSEU
I never knew about the 36s delay for the disagree to occur.