The differences between the Mk.2 and the first 616 I converted aren't anything major. As part of a cosmetic change, the mark 2 got an alteration to the internal filler. Instead of being mounted on an oversize washer with a rubber sleeve taking up the slack, an undersize washer was first slightly bored out, then hammered into place with a hollow drift. The friction fit between the two is very strong. Also, a presta valve cap was used in the blind cap,as it threads more nicely than the original woods valve cap for some reason.
|The barrel washer, about to be fitted to the filler housing.|
The barrel is held in place between the spindle and a drill, the area to cut wrapped with masking tape, and spun fast as a 42tpi craft saw is held against the barrel. The resulting cut is quite neat. If you try this yourself, bear in mind the craft saw teeth cut on on the pull stroke, so set the drill to rotate the barrel against the teeth!
|A craft saw.|