Thanks Brian. Yes I did see that about the direction of rotation, and have been pondering the matter, you solution could well be the best way, as that shaft needs to be removed to do anything with the cam/timing. Bit hesitant to put loctite in there for that reason.
The other thing that did occur was to make the end a shouldered bolt, with a nut on the inside and a locking screw going down from the top of the bearing block. I'll let you know what I end up going with.
I'll get a pic of the needle when daylight is upon us - 3am is not a good time for that sort of activity, Mrs Tel tends to get grumpy.