Looking for a water hose

[r4atthebasin]

I am looking for a water hose for my 1983 R4 - the narrow water hose that goes from the top of the cylinder head to the carb (area) - I have had the rad rebuilt and all the other larger diameter hoses replaced so keen to find one of these so I can get my R4 back on teh road - I have looked in the Der Franzose catalogue but can't see the right one! Any ideas on which one it is on Der Franzose or another source? Hopefully a picture is attached.

 

[plallenuk]

Is it one of these?
http://www.mister-auto.co.uk/en/radiator-hose/gates-3025_g475_a0333025.html
I've had some fairly good success with This website for bits and bobs... If you search by registration number it seems to come up with the right thing.