Ron;
Ya that's the word, cylinder (barrel). I have removed the cylinder from the Ign.,switch. The switch is fairly stiff but servicable, except for the no start on wet days. As I have already installed a different coil on this car ( I have '75 240 eletronic ignition) it's true that a push button for the starter would be simple enough.
So I went out and checked my keys against the doors.
The same key that with a little fussing turns the ign cyl also locks and unlocks the doors, it requires the same fussing (withdraw the key 1/8").

So whadaya think of this idea? THe key is a bad copy, I get a locksmith to fine tune it for me and voila the whole car opens for me! ................... OR the door locks are so old and worn that a stick fiddled around in them would open then....actually no they won't open using my other 120 keys.
This is a new car for me and I"m just putting it all togehther as we speak. So this appears to be a '68 wagon that uses the same keys in the locks and ign. Weird. Thanks for your help in this, I needed another brain to bounce against. P of M.
p.s. do you know where I could get the trim ring that PO destroyed pulling the ignition switch. How many volvos have i seen with messed up dashes cause no one could work out how to pull the Ign switch. A new trim piece would hide the damage a little.