Hi thanks for the responses, I would have room for some 50ml type oiler on the headstock, at the moment it's just a plain hole, and has these fitted already.
Look at this on eBay http://www.ebay.co.uk/itm/352011810617
I was going to buy a few more for the other oiling points but thought I'd look at making a larger wick system ones.
Way I'd make them would be a flange for the bottom to fit the hole in the headstock, drilled and stepped at the edge for a piece of tube to fit to form the cup, a small piece of tube that is a tight fit, traveling the length of the oiler, then solder the assembly together. I've seen that a piece of incited wire works really well as a wick, the surface tension of the oil, gravitating up the steel and forming a drip at the end of the steel.
Edited By Jon Cameron on 01/10/2017 12:36:39