Internal cable straw

Hi all,

I have a Ribble R872 which has internal cables. I replaced the front gear cable the other day and had to throw away the cable straw guide as it was full of gunk. Any idea where I could get more from? I have spoken to Ribble but they don't stock it as it comes with the frame. I asked at my LBS who didn't have anything I could use.

This is what I am looking for but seems to be out of stock. Anyone know of local stock in the uk?

Thanks