Is it possible/feasible to remove the distributor (23D4) from a Twink without removing the Webers?
Yes, its no problem just a bit finicky.
Thanks, Brian. Might be better than trying to replace the points and condenser with it in the car.
Absolutely, but now a 1000 people will tell you to fit electronic ign 
I’m beginning to wonder if sticky centrifugal weights in my distributor are the cause of my engine’s very real reluctance to start when it has been unused for a few days.
I’ve tried just about everything else.
In my experience, the engine will start fairly easily with ign timing off by 20 degrees (crank) either way - which is roughly the total distance moved by the centrifugal advance - so it sounds unlikely to me.
I would check the theory out by just putting a strobe light on while cranking the engine and see roughly where the timing is.
Also, if the weights are sticking to that degree, I’d expect to see quite a lot of jitter in the timing when using a strobe when the engine is running.
Paddy
TO REMOVE THE DIST ----JUST REMOVE THE DIST CAP —LOOSEN THE CLAMP and lift -------however it is wise to do this with the cams and pulley at tdc --front lobes out rear lobes in - timing marks in correct position -and to replace the dist follow the manual exactly ----the low tension wires adjacent to the block --make sure the slot in the rotor is at 6 o’clock as it will turn to the left [anti clock wise] into the correct position as it meshes - this will put #1 at the top slightly right and timing [1342] will be set in correct position — the clamps will be vertical in a line at 90 degrees with the block --put plug in the wire and rotate the dist it will spark confirming #1 plug -otherwise you will chase the thing around for hours trying to get it started—ed