A search of the internet turned up what looked to be a good solution.

What I ordered was an aluminium holder from America that slots into the seat rail and is held tight by a small grub screw, it works really well. The only problem being the finish is crap, and the hole is for a XXXL coke or whatever else they are guzzling in the US. My flat white or Cortado simply falls straight through. The image above shows the purchased unit at the top and a second one I had made in stainless.
I have also decided to change the style of the holder and have messed around with a few ideas, the hole size has also been changed to hold small, medium and large coffee cups.




One of my friends has recently purchased a lovely Pagadoa so made this for him. Please don't point out the obvious mistake, they cut the badge at the wrong angle. Just unbelievable at times, I will get this sorted.

In the end, I have decided to go for the OOO design from the Porsche magazine, first prototype cut and the guy on the laser decided he would make the top hole slightly smaller to fit. Needless to say this has now been changed and all of the holes are identical.

I will produce 10 or so and then send these to the polisher I use.

Looking to achieve this kind of finish.

If there is interest I will have more cut and polished and would prefer to do this all at the same time to minimise the messing about.
Keen to gauge if anyone would like one.
I am hoping that £40 will cover my costs, I haven't spoken/ priced this with my polisher but he isn't usually too difficult to deal with.
Regards
Tom