Veefer Speedo Drive.

My pal turned up on his mk II Saturday night reporting that the speedo had failed. In fact the tag had broken off the drive unit. So we pulled it out and I soft soldered a new one on. Now I’ve previously had to do that on mine, and I have it on the annual service schedule now to strip it out and repack with grease. But mine all comes apart, whilst his seems to be all pressed up (I suspect mine somehow fell apart at some earlier time).

There is a grease nipple on it but my gun wouldn’t seem to work, despite the little ball pressing in easily when I tried it. Is there a particular grease gun tip that will work on this?