Hunter Sata-Lite renovation advice needed!

Hi all,

I'm currently in the process of fixing my old Hunter Sata-Lite which has been in storage for a long time and is in a pretty poor state. The lamp had been stored on its side (big mistake) and the cap has corroded. The screw cap for the bottle has completely disintegrated and the decorative cap now has several holes in it.

The screw cap for the bottle was originally glued inside the decorative cap but I'm thinking if I can just find a replacement screw cap then I can make the bottle water tight again and might be able to re-use the main cap if I can tidy it up - it did require a lot of "persuasion" to remove it.

I've asked Mathmos about their bottle caps but they say theirs are a different size to the Hunter bottles so my main question is, does anyone know the size of cap needed for mine and where I might be able to obtain one? Ideally I'd like to replace the whole cap but I'm guessing finding one will be pretty impossible.

Thanks for any advice,

Leo.