If so I've love to know where from (Shimano 105)
I damaged the smallest one on my CX when I bent the hanger right into the the cassette. The cassette was almost new and it's only the smallest one that was damaged.
Have you looked at sjscycles ?
I know they sell them for mtb cassettes
could always buy a new cassette, use the small cog, keep the rest as a spare & reuse the small cog as it's unlikely to be work out when it comes to replace it.
Having said that; road cassettes take ages to wear out! you have any old cassettes lying around?
Don't Rose bikes sell some?
sjs & Rose, no joy except a very similar looking XT one which might\might not work.
so looks like a new cassette and swap the 11t out, it doesn't get used that much but when I do at the moment it jumps which is a PITA.
All of my knackered spares including the last cassette all went in my mates scrap bin to be weighed in just a week or two ago. Ahh well never mind, another order to rose, need some pedals and BB's too seem to be eating them this year for some reason 😥 Must be my awesome power 😉