The ivory phone was seen in the kitchen on 5th Aug when the tel eng collected the cordless phone damaged in a recent storm.
If JB removed the ivory phone he could not be sure the Bambers would not put it back or plug in one of the other phones.
Actually thinking about it were those old rotary phones capable of being moved around? I thought they were wired in and fixed?
Jeremy had a habit of snooping on the quiet, so would have checked thta night that no phone was in the master bedroom
Besides, what you’re forgetting is that none of the others can speak — Jeremy shot them all dead
It’s more than likely after the broken kitchen phone was taken away for repairs (which was possibly broken by JB...how often do walkabouts break?!) JB put the phone into the kitchen on the excuse he needed to make some calls
IF that phone was fixed in the kitchen socket, which means all the evidence that it was usually in the bedroom is false, then that means it was even easier for JB to take it it off the hook in case, by chance, Nevill had plugged another phone into the bedroom while the mysteriously “broken” walkabout had been sent for repairs just days before
Jeremy knew a heck of a LOT about the current phone situation in the farmhouse considering he no longer lived there!
But as you rightly say, Holly, when Jeremy crept in through the window he had to take the receiver off the hook IN CASE Nevill, by chance, had indeed plugged another one in the bedroom. That makes sense!