Thank you for your reply! Looking at the diagram, the absorber is not going between the actual fins? (number 13)
Also, the damper is conical, one end is wider than other... Let's see, hopefully someone will be able to solve the puzzle

Now I'll need to head out to the mule shed... I don't recall any rubber snubbers on mine... After few cups of coffee..
Sneezles61

Jackie was viewing the 250 head diagram . On the 250 the rubber dampers are tapered ,
but despite what the picture shows they are placed between the front fins .
I've been chasing dampers for the 360 , for my RT2 , and they are proving very hard
to find . I have looked at a number of 360 cylinder heads on Ebay , and the damper
appears to be a straight cylindrical shape , but inserts horozontally between the fins ,
rather than vertically , like the 250 .
I had hoped to be able to locate a NOS 360 example , to provide Jackie as a sample .
Maybe someone else might have more success .

June 2023. I am also looking for a set, but for a 1971 CT1. Sumo rubber web site seems not to exist anymore. Any other suppliers? I am in UK.

Get 50cm of 12mm rubber cord, and cut off as many damper rubbers as you need.

Think some came out new with squashed rubber tube, quite long strips.