Just some other points of interest....the C15 spacer tubes need to be pretty much exactly the same length, otherwise the clutch plate will not lift squarely. The length of the C14 pins does not matter so long as they don't protrude past the end of the C15 tubes. If you fit new C 29 Springs check they are not binding in the C30 spring cups, as this will also stop the outer plate lifting squarely. It is most unfortunate that the outer springs are not able to be adjusted individually, as per a conventional muti plate. Rather than endlessly changing the outer springs around to get a wobble free lift, try and space them as equally as you can with regards to their length, as In the two longest ones opposite each other and so on. With the bike on rear stand, in top gear and clutch disengaged with handlebar lever, rotate rear wheel, and with a texter pen, mark the outer plate where its high point is, and place thin 3/8 ID shim washers between the spring/s and the C27 outer ring. This means the shim will sit over the C15 sleeves, and effectively puts extra load on that spring. It can be tricky but make sure the shim does not jam under the C27 ring plate when the 2ba countersunk screws are tightened. It seems painful, but trust me....it is far easier than endlessly swapping springs to achieve the same result. Generally I have found the nominal length of the C15 tubes to be around 0.945 and 0.950 in length. If the springs are tight in their cups, just linnish them on the outside until they are a free fit......if they bind, you will not be able to get the outer plate lifting evenly. The original Vincent clutch is a complex item and like other features on these machines....is unique to them alone, with regards to a multi plate clutch, I think the original clutch is best, as the lift mechanism was only designed to lift one plate...A multi plate clutch can be made to work ok, but I found only when run dry, and without any wobble from the chainwheel bushes, and so on. That is that a mutiplate needs to run quite true, or else the plates will not free easily. The twin gearbox is almost indestructible, and most blame slow gearchanges and poor shifting on the gearbox. This is in most parts completely wrong, and is almost always due to a poorly set up clutch. Some people I know who actually know Vincents quite well, still believe the clutch is centrifugal.......Go figure....Hope this is of help............Greg.