Hey Guys ..i have a bottleneck sans bottle!! for anyone who may be interested i put masking tape round the neck and used a regular junior hachsaw to score around the neck . then i used MMarios burning string idea, with the string sort of caught in the etched groove (very shallow ). Used running water rather than ice cube and off came the neck..ready to be worked with wet emery paper. Technique needs a little refining..maybe a jig of some kind, but for a none practical bloke i'm well pleased ! Thanks for the inspiration