Hi. I have recently bought an early Halmatic 30 with a roller furling jib. It is not marked up in any way but is odd in that the jib halliard runs up the outside of the aluminium foil, through a bronze sheeve at the top (which rotates with the foil) before returning to the base of the foil where it hooks on. I presume a handy Billy is used to get tension in the jib luff before hooking the halliard on. The top swivel is stainless steel and has a 6mm threaded hole in the side, very near the top. This has nothing in it and I believe it was for a grease nipple. Can anyone identify the system and confirm my thoughts on the 6mm hole. Thank you. Tokita.