Like I said, confirm the size/thread, and i may be able to whip these up no problem.
how do i do that mate dont forget not everyone will have the same can but most seem to be similar 
Been thinking about this; a few ways;
1. Post me one of the originals, which I will return with the machined ones. (easy enough if the can is not yet installed)
2. Put up the ebay link, I will contact the seller.
3. Go into a hardware store/plumbing shop and ask them, or buy/test some fittings and see which threads match.
Regarding the overall design/requirements, if you have specific requirements/dimensions, if you can supply these (a drwaing would be best, but not essential) then I can make whatever EXACTLY to YOUR requirements.
At a punt, thread size is most probably 1/4 BSP, but may be 3/8 BSP on some cans.
IF BOUGHT FROM AMERICA, THE THREADS WILL MOST PROBABLY BE DIFFERENT, BUT THESE\CAN ALSO BE MACHINED.
What do you reckon?