Thank you, I shall send them a message.You may be lucky - back in the day, Shimano tips were often interchangeable across feeder rod ranges, making it easier to find replacements. I bought a tip for an old Technium Diaflash feeder rod from Billy Clarke, Sheffield. They seem to know everything about Shimano spares and might be able to help.
Here is another old email address mailto:firstname.lastname@example.org
You could also try Felindre of Swansea who service all reels and sell tackle. I seem to recall reading somewhere that they were official Shimano spares sellers. Worth a try. http://www.felindreinnovations.co.uk/