I have been having trouble getting the 914 to start. Thought it was the switch at the bottom of the lock cylinder which I have changed before for this problem. This time it was still intermittent weather it would start or not. Finally tracked the problem down to the part of the cylinder blade that fits into the switch is not rotating enough to engage the starter switch. If I remove the switch and put a flat screwdriver into the switch and rotate It starts every time. I am assuming the cylinder is worn and the problem. Is it possible to disassemble the lock cylinder?

Might want to contact @TheCabinetmaker , he is the resident locksmith.

It's possible, but when you pull the actual key cylinder from it's housing, the wafers and springs can go flying into a black hole somewhere. Sounds like something inside has broken. Send it to me and I'll fix it properly for you for minimum cost.
914locks(@)gmail(dot) com.

Thank you!

sometimes the new plastic switches have too much slop in them and in combination with a worn tumbler will not "reach" the crank position. Start with a good plastic ignition switch, THEN remove the lock cylinder and clean and grease and tighten it with two good roll pins

Some of the new plastic switches don't have a stellar reputation. If it works with a screwdriver, then I would "guess"the switch to be ok.
I would indeed check the roll pins.

Click to view attachment

Does the key switch operate smoothly & properly while out of the steering lock assy?